1.We need the same machine

1.We need the same machine ___in your factory.
A.which is being used B.that used
C.as is being used D.as it is being used
2.The teacher asked me some questions___to my paper.
A.relative B.about C.on D.for
3.The engineer said that newly-designed engine was___the old one.
A.as twice powerful as B.powerful as twice as
C.twice as powerful as D.twice more powerful as

A machine后 面 要 跟 修 饰 它 的 从 句
A 有to 在 后 面 ,别 的 都 不 能 用
C twice as powerful固 定 句 形 .如 选 4,就 该 改 为 twice more powerful than