题目内容：

since打头的句子要用什么时态?
列如：Sincet helen is angry ,we
A had better lleaving her alone B should leave her alone
C might as well leave her alone D had rather leave her alone

优质解答

我是师范学校毕业的,
首先这句话的意思是：
因为海伦生气了,我们最好（应该）离她远点,让她静一静.
since引导的句子通常是时间状语从句,主句用一般现在时,从句用现在完成时.
但在这句句子中,since作“由于,因为”理解,不引导什么从句,所以做题时根据句意来做即可.
答案选B
A选项里,leaving改为leave就对了,had better do sth.用动词原形
C选项在本句中涉及到了最佳选项问题,理论上来讲,C也是对的,但因为有B选项的存在,C与B比较,B更加符合句意.
D选项也没这种写法,要么had better do,要么would rather do.