72.______ Nat Turner who led a revolt against slavery in Virginia in 1831.
问题描述：
72.______ Nat Turner who led a revolt against slavery in Virginia in 1831.
a.Where was b.It was c.He was d.it was him
为什么c不行
75.It was ______ late in the evening that the students returned to the dormitories.
a.till b.before c.when d.not until
答案是d我想知道为什么,其他的为什么不行
答
1.it was 是形式主语,因为后面的主语Nat Turner who led a revolt against slavery 太长,所以用it was
2.这个是固定用法,记住就好啦～it was not until～