With a lot of tough problems       , the pilot was still calm, cool and collective under pressure.
#96144
A
solve
B
solved
C
solving
D
to solve
推荐题目
 I couldn't do my homework with all that noise
#88857
A
to go on
B
goes on
C
went on
D
going on
Life is like time. Once _____, it never returns.
#98560
A
to lose
B
loving
C
lost
D
being lost