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.

肾病综合征出现大量蛋白尿其主要机制是

A．肾静脉回流障碍

B．肾血流量增加

C．肾小球上皮细胞足突裂隙增大

D．肾小球滤过膜内皮窗孔径过大

E．肾小球基膜糖蛋白成分变化，负电荷消失