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
Lang Ping , who used to be captain of Chinese Women’s volleyball team, ______volleyball in China for almost twenty years.
#102984
A
have played
B
played
C
was playing
D
had played
---The window is dirty.----I know. It ______ for weeks.
#101155
A
hasn’t cleaned
B
didn’t clean
C
wasn’t cleaned
D
hasn’t been cleaned
The most delicious bread in the world ______ by Mom. Please wait an hour to enjoy it.
#102245
A
bakes
B
is baked
C
is baking
D
is being baked
Luckily good things _________ here to save local wildlife.
#102513
A
are doing
B
are being done
C
had been done
D
will do
As the supermark_______, allthe goods are sold at half price.
#104887
A
has closed down
B
is closing down
C
closed down
D
had closed down