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
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He        to keep this book for a month.
#99525
A
will allow
B
will be allowed
C
allows
D
allowed
Every means ______ tried, yet no result ______encouraging up to now.
#103827
A
have been ...is
B
has been...has been
C
have ...has been
D
has...is
 — Tom, will you attend the press meeting to be held this morning? — But I ______ anything about it.
#99852
A
wouldn’t be told
B
haven’t been told
C
haven’t told
D
am not told