China ______ a lot of people moving to urban areas in the last 20 years. However, many migrants  left their families behind.
#100122
A
saw
B
sees
C
has seen
D
had seen
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 The police _____ the lost boy everywhere when he suddenly turned up in a supermarket.
#102062
A
searched
B
searched for
C
was searching
D
were searching for
-------- The window is dirty. --------- I know. It __________ for weeks.
#101585
A
hasn’t cleaned
B
didn’t clean
C
wasn’t cleaned
D
hasn’t been cleaned
It was the second time that we ______ in holding such important parties.
#100119
A
had succeeded
B
succeed
C
succeeded
D
have succeeded
I feel so excited! At this time tomorrow morning, I ________ to Shanghai.
#101277
A
will be flying
B
will fly
C
have been flying
D
have flown
By the time she ________ tomorrow, the work ________.
#103599
A
arrives ; will be finished
B
arrives ; will have been finished
C
will arrive ; will have been finished
D
arrives ; will have finished