用所给动词的适当形式填空。

1. My brother started______ (learn) English when he was 5 years old.

2. Welcome to our class. I need______ ( ask) you some questions.

3.I will think about______ ( become)  an engi-neer.

4.We decided______ (go) hiking this summer holiday.

5.—How long ______ you ______ (study) at the school? .

   —For a year.

6.He______ (be) a college student for two years.

按国家有关规定，砂瓦分为平形砂瓦、扇形砂瓦、平凸形砂瓦和（）5个品种。

A、圆头砂瓦

B、锥形砂瓦

C、梯形砂瓦

D、针形砂瓦