编制材料计划应遵循(),严肃性和灵活性统一的原则。
A、节约原则
B、实事求是
C、留有余地
D、综合平衡
参考答案:B, C, D
按规律填数:1,1,2,3,5,______,______,______.
—Could you tell us _____ to travel from Earth to Mars by spaceship?
—It takes months, I think.[ ]
A. how far it takes
B. how long it takes
C. how long does it tak
D. how soon does it take