6.They ________ extensive and possibly dangerous actual flight training.
A. undertake
B. undergo
C. underplay
D. underuse
7.They will get the preparation done early in May.
A. 他们五月初就能让别人准备完工作
B. 他们五月初就能准备好工作
C. 他们早在五月份就能把准备工作做完
D. 他们五月初就能把准备工作做完
8.Weather _______， we‘ll go out for a walk.
A. permitted
B. permitting
C. permits
D. for permitting
9.I don‘t think the charge for overhauling the equipment is excessive in _______ to its size.
A. correspondence
B. equation
C. proportion
D. dimension
10.It is difficult to understand this kind of _______ calculation.
A. intricate
B. varied
C. indispensable
D. equable
