With the help of high technology, more and more substances _________ in the past years.
#101033
A
discovered
B
have discovered
C
had been discovered
D
have been discovered
推荐题目
It is really a pity that I can not attend your wedding party this weekend. I _________ a very important international conference in Paris then.
#99261
A
have attended
B
are attending
C
have been attending
D
will be attending
He couldn’t stand the noise made by the factory, so he wrote a letter to the newspaper to _________ about it.
#100769
A
introduce
B
quarrel
C
care
D
complain
He feels that his health ____ owing to ____ a long walk every other day.
#104858
A
is improving; taking
B
has been improved; being taken
C
improved; taken
D
is improving; have taken
—How was the journey?—Tiring! I caught the train at the last second but all the seats . I stood all the way.
#102698
A
had been occupied
B
had occupied
C
would occupy
D
would be occupied
– Jenny , how was your trip to Beijing ? - Oh , I missed it . I wish I ________ my vacation there .
#102991
A
am spending
B
will spend
C
have spent
D
had spent