A、it
B、that
C、it is
D、that is
答案：A
解析：这道题考察的是代词的用法。正确答案是A: it。
在这个句子中，"it" 作为形式宾语，代替了后面的不定式动词短语"to learn English grammar"。所以句子的正确表达应该是"I found it difficult to learn English grammar."，意思是"我发现学习英语语法很困难"。
A、it
B、that
C、it is
D、that is
答案：A
解析：这道题考察的是代词的用法。正确答案是A: it。
在这个句子中，"it" 作为形式宾语，代替了后面的不定式动词短语"to learn English grammar"。所以句子的正确表达应该是"I found it difficult to learn English grammar."，意思是"我发现学习英语语法很困难"。
A. know who is he
B. know who he is
C. knows who is he
D. knows who he is
A. who is
B. who am
C. that is
D. what is
A. set out
B. set off
C. set about
D. set down
A. will take
B. would take
C. take
D. took
A. do
B. does
C. did
D. would do
A. when
B. what time
C. weather
D. whether
A. in front of it
B. in front of whose
C. in front of which
D. in the front of which
A. How a great success
B. What a great success
C. How great success
D. What great success
A. that you really need
B. that you are really needed
C. what you really need
D. that you are really needing
A. wouldn’t do
B. wouldn’t have done
C. won’t do
D. have not done
