填词完成句子，首字母已给出。

1. L_____ Sunday I went to visit my uncle.

2. Li Ping is studying for the math t_____.

3. The math problem is a l_____ difficult. I can't work it out.

4. The teacher told me to s_____ at school, because I talked in class.

5. He is thirteen. He is a m_____ school student.

有关重症肌无力的临床表现，下列哪项不对（）

A.休息后缓解

B.新斯的明试验阴性

C.肌电图示低频重复递减

D.晨轻暮重

E.可伴胸腺瘤