用恰当的介词或副词填空

The reason ________ building the pyramids ________ Egypt is still unknown even today．

用恰当的介词或副词填空

I ran ________ an old friend in the street the other day．

用恰当的介词或副词填空

The world we live in is filled ________ mysteries．

Ⅰ．根据括号内的要求，写出单词的正确形式

1．missing(同义词)________

2．employee(动词)________

3．discuss(名词)________

4．unexplain(形容词)________

5．lucky(名词)________

6．reason(同义词)________

7．exploration(动词)________

8．evidence(形容词)________

9．separate(名词)________

10．advanced(名词)________

11．following(动词)________

12．question(同义词)________

13．photo(复数)________

14．discover(名词)________

15．fall(过去式)________(过去分词)________

16．protect(名词)________

17．the former(反义词组)________

Ⅱ．请用上面单词的适当形式完成下面句子

1．The ________ for my laterness is that I missed my bus．

2．The unfortunate gentleman had been ________ for some days．

3．He tried his ________ at farming and made a lot of money．

4．If the factory is closed many men will face ________．

5．The question is still under ________．

6．It was ________ that the policy was a failure．

7．England is ________ from France by the Channel．

8．Would you be kind enough to ________ the meaning of this expression to me?

9．A big program of oil ________ has begun offshore．

10．If I had to choose between fish and chicken, I’d prefer ________．

11．Our medical insurance offers ________ for the whole family in event of illness．

12．It’s impossible to know in ________ what will happen．

13．The main events were as ________ ：firstly, the present’s speech, secondly the secretary’s reply and thirdly, the chairman’s summing up．

14．Scientists have made many important ________．

15．Would you like to see the ________ I took of the Great Wall the other day?