so as to 的用法

netmovr

climatic shifts are so gradual as to be indistinguishable at first from ordinary fluctuation in the weather.

 

A,

B. so gradual they can be indistinguishable

C.. so gradual that they are unable to be distingguished.

D. gradual enough not to be distinguishable.

E. gradual enough so that one can not distinguish them

俺选C，因为被动语态好像没有问题。但答案是A， 请各高人指点~

谢谢

netmovr

谢谢LS们，思路清晰多了~

woodlittle

主动优先于被动语态

when so that and so as to happens to having the same meaning,

then we should choose positive tense

thanks sharing

carollai

risk 在这里作为概率讲是不可数 应该直接排除