應(yīng)該是such as to.
本題主要考察A和B的區(qū)別,C和D比較容易排除
A和B的區(qū)別如下：
so as to:
為的是,以便
例句與用法:
1.He ran quickly so as to catch the last bus.
他跑得很快以便趕上那末班車.
2.The two lovers dropped back so as to be alone.
那對(duì)情人落在后面,為的是兩人好單獨(dú)在一起.
such as to:
達(dá)到這樣的程度以致
例句與用法:
1.His speech is such as to incur enmity.
他的演說會(huì)引起別人的敵意.
2.Her madness is not such as to fill her mother with despair.
她還沒有瘋到令其母親絕望的程度.