In time of serious accidents, ________ we know some basic things about first aid, we can save lives.
#30162
A
whether
B
until
C
if
D
unless
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 __________I see him, he looks sad.
#31022
A
Every now and then
B
Every now and again
C
Every so often
D
Every time
Look at the trouble I am in! _______I had followed your advice.
#31562
A
Only if
B
If only
C
Even if
D
So long as
The teacher talked in a very low voice_____make himself________, clearly.
#34188
A
in order to; hear
B
so as not; hear
C
in order not to; heard
D
so that to; heard