—When did the computer crash?—This morning，while I ________ the reading materials downloaded from some websites.(2012·福建)
#99575
A
have sorted
B
was sorting
C
am sorting
D
had sorted
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They became friends again that day. Until then, they _____ to each other for nearly two years.
#101733
A
won't speak
B
haven't spoken
C
hadn't spoken
D
haven't been speaking
—How long can I keep the book? —A week. You _____to return it by Monday.
#103328
A
expect
B
will expect
C
are expected
D
will be expected
---Could I have a window seat ? ---All right. Your flight _____ boarding at Gate 18 at 2:15.
#103082
A
have begun
B
began
C
is to begin
D
begins
It’s very dangerous to _______ these viruses without any protection.
#99965
A
be exposed to
B
expose to
C
expose
D
be exposing to