The reason why Malaysia Airline Flight370 disappeared remained_____.
#88645
A
look into
B
to be looked into
C
looking into
D
to look into
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I suggest that the person ____put into prison.
#93214
A
refer to
B
referred to was
C
referred to be
D
referring to should be
The digital dictionary I had        the other day cost me a lot.
#95729
A
repaired
B
repairing
C
to repair
D
to be repaired