选词填空。

1. We _____________ (has, have) a new teacher.

2. Let _____________ ( us, is) clean the window.

3. How many _____________ (pen, pens) do you have?

4. _____________ (I, My) schoolbag is heavy.

5. _____________ (I, He) likes music.

6. He's good _____________ (for, at) math.

关于痴呆，不正确的是（）

A.痴呆是老年人的常见障碍

B.常见类型是Alzheimer和血管性痴呆

C.Alzheimer为全面性痴呆，多在60岁左右发病

D.血管性痴呆以多梗死性痴呆和皮质下动脉硬化脑病为多见

E.多发性脑梗死性痴呆发病缓慢，隐袭起病