2008年8月底，在市场上出售的某些品牌的婴幼儿配方奶粉及液态奶中被检测出三聚氰胺，这是一些不法商家为了提高奶粉及液态奶中的含氮量而添加的。一般来说，每100克蛋白质平均含氮量为16克，这些氮主要存在于蛋白质的[ ]

A．―CO―NH―

B．游离的氨基

C．游离的羧基

D．R基

单词拼写。

1. She's s______ herself to try to lose weight.

2. I'm looking f______ to your early reply

3. He particularly enjoyed playing a t______ on the three men.

4. Young people want i______ from their parents

5. The new president had to face n______ and international issues.

6. On your ______ (到达) at the hotel, please wait for further instructions

7. Look! He is an ______ (精力充沛的) child

8. She was ______ (授予) a medal for her bravery

9. They celebrated the festival only to satisfy their ______ (祖先)

10. Our country paid much attention to the ______ (农业的)workers