Experiments of this kind in both the U．S．and Europe well before the Second World War．
#102432
A
have conducted
B
have been conducted
C
had conducted
D
had been conducted
推荐题目
To understand the complex situation completely requires more thought than ________ so far.
#102247
A
gave
B
has given
C
has been given
D
is being given
--- Do you want a lift home? --- It’s very kind of you , but I have to work late in the office . I over slept this morning because my alarm clock _________ .
#100257
A
doesn’t go off
B
won’t go off
C
wasn’t going off
D
didn’t go off
With the introduction of digital equipment, a growing audience_______ back to the cinema in the past years.
#102048
A
have been brought
B
were brought
C
has been brought
D
had been brought
—Where is your brother? —He has gone to Beijing. He back in three days.
#101825
A
will come
B
comes
C
has come
D
came
--The window is dirty.----I know. It ______ for weeks.
#101363
A
hasn’t cleaned
B
didn’t clean
C
wasn’t cleaned
D
hasn’t been cleaned