下列的措施中，对保持生态环境最有利的是（ ）
A：把大片沼泽地开垦为家田
B：在菜地中洒家药以杀死菜青虫
C：在田间施放射性引诱剂，干扰雌雄害虫之间的通讯
D：把工业废水排入发生“赤潮”的海域，让那些有毒藻类死亡
把多項式a2﹣4a分解因式，结果正确的是（ ）
—Do you know_______? —Sorry, I don't know.
⑴Look at my new cap.____ A. Hello, Tim.
⑵What color is it?____ B. How nice!
⑶This is my brother, Tim.____ C. Goodbye
⑷Are you Bobby?. ____ D. Yes, I am.
⑸ Goodbye.____ E. It's red.
Johndidn't go to work on Sunday afternoon. He ____ a horse.
