Copernicusmaintainedthattheearth_____roundthesun.
A
表述永恒的真理或客观规律用一般现在时, 不管主句谓语用什么时态。 而“地球 绕着太阳转 ”是客观规律,所以选 a
Thosepeople_____ageneralunderstandingofthepresentsituation.
Thedriverpulled_____atthetrafficlights.
Hewasvery_____togo,buthehadnochoice.
_____youunderstandthisrule,you‘llhavenodifficultyindealingwithsuchproblems.