A new spaceship was ____ at Cape Kennedy yesterday.

A.motivated

B.released

C.transmitted

D.launched

How will NASA make its new spaceship？ 查看材料

A.It will base its design on that of the Apollo program.

B.It will use parts only from the Apollo program.

C.It will make use of the Apollo program and the space shuttle.

D.It will develop new designs and make new components.

Laser-dopple radar is especially valuable in space missions because it ______ .

A．is one thousand times more precise than microwave radar

B．provides precise measures of the velocity of space vehicles

C．is a new system of radar

D．can measure the movement of a spaceship less accurately than a microwave radar

What does the news item mainly talk about？

A．The Curiosity rover finally got on Mars after eight months cruising.

B．NASA launched a new spaceship—the Curiosity rover.

C．Astronauts getting on Mars would develop cancer due to radiation.

D．Astronauts can be protected from the radiation by lots of methods.

he astronauts carry important supplies with them on the spaceship — food, water and air. Sometimes there are problems on the spaceship, and the astronauts have to understand how the spaceship works in order to repair the problems. In a way, all of us are really on a spaceship, the planet Earth. We move around the Sun at 18 miles per second and never stop. On our spaceship we have four billion people and a limited supply of air, water and land. These supplies, just like the limited supplies on the astronauts spaceship, have to be used carefully because we cant buy new air, water or land from anywhere else. Everyone needs air, water and land to live — this is our environment. The environment on our planet is a closed system; nothing new is ever added. Nature recycles its resources. Water, for example, evaporates and rises to form. clouds. This same water returns to the earth as rain or snow. The rain that falls today is actually the same water that fell on the dinosaurs 70 million years ago. Over the years, people have changed the environment. We have poured back into the land, air, and water more wastes than nature can clean. So we have pollution today. To continue to survive, we must learn how to use the Earths resources wisely, without destroying them. To save the spaceship Earth, we must cooperate with nature and learn better ways to use, not to abuse our environment. Questions 20 to 22 are based on the passage you have just heard. 20. Which would be the best title for the passage？ 21. Which is true according to the passage？ 22. What can we conclude from the passage？20．

A．The present population on earth is fourteen billion.

B．Water is recycled every seventy million years.

C．The planet earth travels around the sun at 18 miles per second.

D．The earth is compared to a spaceship because they both travel around the sun.

Laser-dopple radar is especially valuable in space missions because it ______.

A．is one thousand times more precise than microwave radar

B．provides precise measures of the velocity of space vehicles

C．is a new system of radar

D．can measure the movement of a spaceship less accurately than a microwave radar

of a new system of radar that makes use of a beam of light is said to be ten thousand times more accurate than the best comparable system of radar that uses microwaves.

The model has shown that this radar system, known as laser-dopple radar, can measure with absolute precision speeds varying from spaceship orbital injection(进入) velocities(速度) of five miles per second down to virtual stops-speeds of less than one-thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous(对接) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ship's skin, or a nudge could knock the station out of its orbit.

The light-beam radar, which operates at a frequency of trillions of cycles(百万兆) per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.

Laser-dopple radar ______.

A．measures the movement of a spaceship by means of light beam

B．makes use of microwaves

C．makes use of sound waves

D．both A and B

听力原文： In a way, all of us are on a spaceship, the planet Earth. We move around the sun at 18 miles per second and never stop. On our spaceship we have six billion people and a limited supply of air, water, and land. These supplies have to be used carefully because we can't buy new air, water, or land from anywhere else.

The environment on our planet is a closed system: nothing new is ever added. Nature recycles its resources. Water, for example, evaporates and rises as visible drops to form. clouds. Then the water returns to earth as rain or snow. The rain that falls today is actually the same water that fell on the land 70 million years ago.

Today, the Earth is in trouble. Factories pour dirty water into rivers. Many fishes die and the water become unhealthy for people to drink, Cars and factories put poisonous gas into the air and cause plants, animals and people to get sick. People throw bottles and paper out of their car windows, and the roadside becomes covered with all sorts of wastes. Over the years, people have changed the environment, and at the same time we cause pollution.

To continue to survive, we must learn how to use the Earth's resources wisely. We have to change our habits and stop dumping such enormous amounts of industrial waste into the water and air. We must cooperate with nature and learn better ways to use, not abuse, our environment.

(37)

A．Because both have a limited supply of air, water, and other resources.

B．Because the Earth moves around the sun as fast as a spaceship.

C．Because we can travel to outer space.

D．Because the Earth never stops moving.

of a new system of radar that makes use of a beam of light is said to be ten thousand times more accurate than the best comparable system of radar that uses microwaves. The model has shown that this radar system (known as laser-doppler radar) can measure with absolute precision speeds varying from spaceship orbital injection velocities (速度) of five miles per second down to virtual stops—speeds of less than one ten thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous (会合, 会合点) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ships skin, or a nudge (轻触) could knock the station out of its orbit. The light-beam radar, which operates at a frequency of trillions of cycles per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station even at a small fraction of an inch per second. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.

Laser-doppler radar makes use of______.

A．light

B．microwaves

C．sound waves

D．both A and B

请根据短文内容，回答题。

Travel to Moon

The National Aeronautics and Space Administration (NASA) has announced plans to return people to the moon by 2018. "And this time," according to a NASA press release, “we&39;re going to stay."＜br＞

NASA wants to make a new spaceship for the missions using parts from the Apollo program,which first took people to the moon in 1969, and the space shuttle. NASA says the new Crew Exploration Vehicle (CEV) will be "affordable, reliable, and safe".＜br＞

The CEV will be able to hold four astronauts. The plan is to have the CEV dock (对接) in space with the lunar- the vehicle astronauts will use to land on the moon- which will be launched separately into space. The CEV will then travel to the moon and all four astronauts will walk on the moon.＜br＞

The first m, oon missions are expected to last up to seven days. Exploration and construction of a moon base will be the astronauts&39; top priorities (最优先考虑的事). NASA hopes to have a minimum of two moon missions a year starting in 2018. This will allow for quick moon base construction, constant scientific study, and training for future missions to Mars.

What is new in NASA‘s plan to return to the moon by 2018？ 查看材料

A.People will land find remain on the moon

B.Equipment will be carded and installed there

C.More CEVs will be made regularly

D.A special device will be used in landing

ppear. They share a number of similarities with each other—as well as some important differences.

Manned submersibles.(潜水器), like spaceships, must maintain living conditions in an unnatural environment. But while a spaceship must simply be sealed against the vacuum of space, a submersible must be able to bear extreme pressure if it is not to break up in deep water.

In exploring space, unmanned vehicles were employed before astronauts. In undersea exploration, on the other haled, men paved (铺路) the way, and only recently have unmanned remote-operated vehicles (ROVs) been put to use.

One reason for this is that communicating with vehicles in orbit is much easier than talking to those underwater. A vacuum is an ideal medium for radio communications, but underwater communications are limited to much slower sound waves. Thus, most undersea vehicles—particularly ROVs—operate. at the end of long process.

For a similar reason, knowing where you are undersea is much more difficult than in space. A spaceship's position can be located by following its radio signal, or by using telescopes and radar. For an undersea vehicle, however, a special network of sonar (声纳) devices most be laid out in advance on the ocean floor in the area of a dive to locate the vehicle's position.

Though undersea exploration is more challenging than outer space in a number of respects, it has a distinct advantage: Going to the ocean doesn't require the power necessary to escape Earth's gravity. Thus, it remains far less expensive.

People did not begin to use unmanned vehicles in undersea exploration until recently because of ______.

A．the ocean depths

B．the communication problem

C．the movement of waves

D．the problem of vacuum