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
Betty will ring me up as soon as she ______ in Beijing.
#101706
A
arrive
B
arrives
C
arrived
D
will arrive
Betty and Arthur ____ on separate holidays in a few days’ time.
#101734
A
go
B
going
C
are going
D
went
Had you taken the doctor’s advice yesterday, you ____ all right now.
#103004
A
are
B
were
C
would be
D
would have been
Watching the online open courses of some famous European and American universities _______a new fashion among white collars in China over the past few months.
#102958
A
became
B
had become
C
has become
D
becomes
By the time my parents reached home yesterday, I _____ the dinner already.
#103615
A
had cooked
B
cooked
C
have cooked
D
was cooked