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
By the time you arrive home, I ____, so please don’t make any noise when you come in.
#104303
A
shall have been sleeping
B
shall have slept
C
shall sleep
D
shall be sleeping
No one can tell how many sufferings the kidnapped boy ________ when he was rescued yesterday.
#102133
A
had
B
has had
C
had had
D
would have
– Shall we go out for lunch?– Don’t disturb me. I ______ the letters all morning and ______ six so far.
#100998
A
write; wrote
B
wrote; have written
C
was writing; wrote
D
have been writing; have written
Will you help me to look for an important paper I left in my office this morning as soon as you _______？
#102585
A
arrived
B
arrive
C
will arrive
D
would arrive
----- You seem in low spirits. Anything wrong?----- I ______ in the important exam. I let my parents down.
#101361
A
fail
B
failed
C
has failed
D
had failed