这是一部不朽的世界文学名作，它再现了古代希腊社会的图景，是研究早期希腊社会的重要

阅读理解

Boy: Oh, no!  My book isn't in my backpack! Where is it?

Girl: Your book is on the table.

Boy: OK. My keys? Where are my keys?

Girl: Your keys are in your backpack.

Boy: Yes,yes. Where are my pencils?

Girl: They're under the bed.

Boy: And my hat? Can you see?

Girl: It's on the bed.

Boy: Where's my pencil case?

Girl: It's on the chair. Oh ...no, it isn't. That's my pencil case.

1. His book_______in his backpack.    

A. is        

B. isn't        

C. are        

D. aren't

2. His pencils are_______the bed.    

A. on      

B. in            

C. to          

D. under

3. His pencil case_______on the chair.      

A. is      

B. are          

C. isn't      

D. aren't

4. _______pencil case is on the chair.   

A. His    

B. Her        

C. My        

D. Your

放大电路设置静态工作点目的是（）。

A、提高放大能力

B、避免非线性失真

C、获得合适输入电阻和输出电阻

D、使放大器工作稳定

如何运用实践原则？

男，24岁。低热、右下腹痛、腹泻3个月。有时腹泻便秘交替。临床考虑克罗恩病。

上述病理改变如果来源于肠黏膜，最可能活检的部位是（）

A.阑尾

B.直肠、乙状结肠

C.降结肠

D.空肠

E.末端回肠与邻近结肠

简述导频污染优化过程。