Probably you have seen photos of the Grand Canyon（峡谷）, the great valley in the desert country of Ari...

查看本题答案

包含此试题的试卷

To see To have seen Seeing Having seen

Have, seen, have, seen Did, see, did, see Have, seen, did, see Did, see, have, seen

that who what whom

A. would have seen must have seen may have seen can have seen

Have… seen… did… see Did…see…die…watch Have…seen… have… seen Did…see…have…seen

heard heard of listened to listened

Have you seen; have seen Have you seen; saw Did you see; have seen Did you see; saw

Did you see; did you see Have you seen; did you see Do you see; have you seen Have you seen; have you seen

that who what whom

done taken built programmed

If you were read As you read Read Reading

since when after before

shortly currently lately probably

may not sit in the library probably don't know its background may not have practiced on reading it probably think it is too easy for you to read

Much as I have travelled As long as I have travelled Now that I have travelled so much As I have travelled so much

can’t have seen should not have seen must not have seen need not have seen

shortly currently lately probably

a second time and you quite a different described

To see To have seen Seeing Having seen