根据所给汉语提示,写出空缺处单词正确形式。

1. What are you so ______(紧张) about?

2. Some children are afraid of the ______ (黑).

3. You can ______(辨别) a person's voice on the phone .

4. He uses a pair of _______(眼镜) now.  

5. This guy is definitely       (笨)  

T细胞不能

A．产生细胞因子

B．直接杀伤靶细胞

C．参与对病毒的免疫应答

D．介导ADCC效应

E．诱导抗体的类别转换