请教语法，大虾请指点！

yed02

1. Mahogany is often considered the finest cabinet wood because they has most of the qualities desired for furniture making.

C错没问题。我觉得A该是：considered as？

2. How many people realize that agriculture is a source of raw materials for clothing and to shelter?

D错没问题。但是这不是疑问句么，为什么没有助动词提前？我觉得people 前应有do！

3.The situation comedy has proved to a remarkably durable commercial television format.

B错。此处的prove 为什么不用被动？

一个人的圣经

consider可以加as

但是更多的时候,consider是作为一个接双宾语的词在托福中出现.

类似的还有elect,make等等

vincentshbj

consider as或者consider to be 都可以。但是也可以把to be 省略