I know one of the things _____I was unsure about was _____ hard it would be to climb   this mountain.
#65979
A
that; how
B
what; how
C
which; what
D
/; what
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The floor is so dirty .Would you please     ?
#59450
A
to mop up it
B
mop up it
C
to mop it up
D
mop it up
How pleasant the picture is to _________!
#65956
A
be looked at
B
being looked at
C
looking at
D
look at