With the help of high technology, many new substances（物质）______in the past years.
#102927
A
discovered
B
have discovered
C
had been discovered
D
have been discovered
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I called Mary many times yesterday evening, but I couldn’t get through. Her brother _________ on the phone all the time.
#101197
A
was talking
B
has been talking
C
had talked
D
talked
- I hear that Jason is planning to buy a car. -I know. By next month, he _ enough for a used one.
#99302
A
will have saved
B
will be saving
C
has saved
D
saves
The pen I _______ I _______is on my desk, right under my nose.
#104524
A
think; lost
B
thought; had lost
C
think; had lost
D
thought; have lost
---Can you tell me by whom the speech next Friday?---Mr. Green, our geography teacher.
#99020
A
is given
B
be given
C
will give
D
will be given