如图是一个长骨的结构，据图回答下列问题： （1）写出图中下列番号的结构名称：

给你一只电铃，一只小灯泡，两个开关，一个电源，若干导线，要求连好电路后使得只闭合S₁时 ，电铃响，指示灯亮，只闭合S₂时，电铃响，指示灯不亮，试画出电路图。

下图为果蝇某一条染色体上的几个基因示意图，下列叙述正确的是

A．R基因中的全部脱氧核苷酸序列都能编码蛋白质

B．R、S、N基因中只有部分脱氧核苷酸序列被转录

C．每个基因(如：S片段)是由成百上千个核糖核苷酸组成的

D．若N基因的编码区中有一个碱基对的替换，一定会引起生物性状的改变

完成句子。

1. They came back from vacation a day earlier _______ _______. (比预期的)

2. He thought his parents _______ _______ _______ (对……苛刻) on his brother.

3. Going to a British high school for one year was a very enjoyable and exciting _______ (经历) for one.

4. This ______ ______ (听上去像) my school in China.

5. He also told us that the best way to earn respect from the school was to work hard and

    ______ ______ ______ (获得高分).

6. I found it was a bit ______ (具有挑战性的) for me.

7. You weren't ______ (应该) to come home until tomorrow!

8. I used to go to the gym three times a week, but I don't _______ _______ (锻炼) any more.

9. Things change so quickly! I'm now in hospital recovering from _______ ______ (肝衰竭).

10. Don't damage your health for a slim and ______ (有魅力的) figure.

类风湿关节炎的基本病理改变是（）。

A.滑膜炎

B.血管炎

C.类风湿血管炎

D.类风湿结节

E.坏死性小动脉炎

请你简述敬队礼的要领？