根据括号内的汉语提示，完成句子。

1. When he was in his ______ (四十多岁), he took an active part in the battle against the Qing dynasty.

2. There are many new______ (发现) in recent years.

3. Spitting in public is ______ (禁止), everybody should have good habits.

4. It's ______ (必要的) for us to master computer technology.

5. ______ (大体) speaking, different star signs have different characteristics.

6. An old man was found ______ (躺在) on the road.

骨骼肌中的乳酸脱氢酶以下列哪一种为主（）

A.LD₁

B.LD₅

C.LD₃

D.LD₄

E.LD₂