题目

1.As____turns out,these birds are quite intelligent and seem to have a powerful memory.
a.that b.it c.what d.who
2.He flew into the water,___that as he swam into the ocean,a shark was swimming towards the shore.
a.not realizing b.realizing not c.not realized d.realized not
3.Advancements in science___for thousands of years as far back as the ancient Greeks and their effects are becoming ever more noticeable.
a.occurred b.are occurring c.have occurred d.had occurred
4.In the next class,some particular cases will be introduced to students___maths problems can be solved in a wise way.
a.who b.when c.which d.where

提问时间：2021-03-15

答案

B.it 是形式主语,真正的主语是后面的these 句子.

A.现在分词伴随状语,not放在分词前面

C.for..years说明是现在完成时

D.where定语从句修饰前面的cases,在案例中