【单选题】CTL细胞具有（）。

A.辅助性T细胞(Th)

B.细胞毒T细胞(CTL或Tc)

C.NK细胞

D.中性粒细胞

A.CTL

B.B细胞

C.NK细胞

D.Th

E.巨噬细胞

A.Th细胞

B.CTL细胞

C.B细胞

D.巨噬细胞

A.NK细胞

B.CTL细胞

C.CD8+T淋巴细胞

D.B淋巴细胞

E.CD4+T淋巴细胞

A.表型为CD25+F0xp3+

B.可特异性连续杀伤靶细胞

C.主要分泌IL-2和IFN-y、促进杀伤病毒感染的靶细胞

D.只能识别由CD1分子递呈的抗原

E.CD4+T细胞受抗原刺激分化而来

A.具有明显的地域人群分布特点

B.儿童发病为主，男孩更为多见

C.发生部位以中面部为主，临床过程高度侵袭性

D.与EBV高度相关，EBV原位杂交阳性

E.大部分NK细胞来源，少数为NK样细胞毒性T细胞来源

听力原文：M: Hi, Vivian. What are you doing here？

W: Hi, Steve. I'm having a bit of trouble finding some of the stuff I need.

M: What're you looking for？

W: Well, I'm just trying to find out something about the use of steel in building construction. Do you have any idea？

M: Frankly, I don't know much about this. What about the library？ There's a database on the computer, and most of the stuff you need is catalogued. You can find it somewhere.

W: Yes, but that's the easy part! Then you have to find the book you want on the shelves, and you often find that it's out already.

M: I know what you mean ! Then you have to line up to borrow it, if it's CTL.

W: CTL？ What's CTL？

M: It means "confined to library" : you know, it means you can't take it out. You have to read it in the library.

W: It seems easy, doesn't it？ But you have to reserve it, and then you may want to photocopy bits of it, or make notes--and there never seems to be enough time.

M: Hmm! In your shoes, I think I'd have a word with our tutor.

W: I think I'll do that! Thanks! See you later. Bye!

M: See yah! And good luck !

23. What trouble is Vivian having now？

24.According to Vivian, what is the biggest difficulty in borrowing CTL books？

25.What does Vivian decide to do finally？

(20)

A．She has lost some of her important stuff.

B．There is something wrong with her eyes.

C．She doesn't know how to use steel to build construction.

D．She doesn't know where to get the information she need.