when the air pressure is greater, ______.

The man felt funny about his ear. What did the woman explain to him？

A．It's the air pressure.

B．His ears have some problem.

C．He is hungry.

It's important to have vapor seals on the warm side to ______.

A．avoid gas when the air cools

B．avoid mist when the air cools

C．avoid rapor when the air cools

D．avoid moisture when the air cools

When we are sleeping we______.

A．need less air

B．need more air

C．don't need air at all

When a storm is blowing, what will happen？

A．The air will be still.

B．The air will be full of dust.

C．Faraway objects may look vague.

D．The pressure will drop.

Scientists generally focus on air temperatures when studying global warming.

A．Right

B．Wrong

C．Not mentioned

When the warm air from the sea surface begins to rise, it ______.

A．creates an area of low pressure

B．supplies cold air to the eye of a hurricane

C．increases the sea-surface temperature

D．strengthens the rotation of the earth

A．in warm air

B．in cold air

C．when it reaches the polar region

D．only when the clouds are down low

Ihate his adopting an air of importance when he is talked to.

A) adapting

B)assuming

C) effecting

D)breathing

When filled with a gas______ lighter than air, a balloon becomes buoyant and rises.

A．much

B．more

C．less

D．little