Often major economic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the financial markets.A.so gradual as to be indistinguishableB.so gradual so that they can be indistinguishableC.so gradual that they are una

Often major economic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the financial markets.A.so gradual as to be indistinguishableB.so gradual so that they can be indistinguishableC.so gradual that they are una
Often major economic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the financial markets.
A.so gradual as to be indistinguishable
B.so gradual so that they can be indistinguishable
C.so gradual that they are unable to be distinguished
D.gradual enough not to be distinguishable
E.gradual enough so that one cannot distinguish them
想知道选项的错误,答案是说不能用be able/unable to be done,我想知道是不是因为able只能用于人,所以没有被动语态?

Often major economic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the financial markets.A.so gradual as to be indistinguishableB.so gradual so that they can be indistinguishableC.so gradual that they are una
A:正解
B:so 重复,indistinguishable 用错
C:unable 有生命的物体做主语
D：只听说有enough to的
E：没听过有 enough so that这种用法
以上是个人见解,gmat 750

先给你概括下这道题，一共四个面包。其中三个平分给m个学生，另一个平分给（m-4）个学生。 Carol是从每个面包都吃一块，问她吃的是多少。那么C吃的