根据句意及首字母提示补全单词。

1. —Can you come to my home for dinner?

    —S_______, I'd love to

2. I'm ill ,so I have to see the d________

3. I have t________ much homework to do this weekend.

4. Thanks for h________ me with my English

植物的茎具有向光性的原因是（）

A.向光一侧长得快

B.背光一侧生长素多

C.向光一侧生长素分布多

D.背光一侧没有生长素