高一英语选择题Ifyoubeintimefortheearlybus,besuretogetupbeforefiveinthemorning.A,aretoB,areabouttoC,aregoingtoD,aredueto请告知理由,谢谢

Question

高一英语选择题
If you____ be in time for the early bus ,be sure to get up before five in the morning.
A ,are to B,are about to C, are going to D,are due to
请告知理由,谢谢

Answer 1

选A
因为be to do 是最正式的将来时的用法,但是不是将来时的will,正好用在这个条件状语从句的从句中
B 不能和具体的时间状语连用
C 是将来时,要首先排除（主将从现）
D be due to do sth表示预定好了要做某事,于此题矛盾,因为这只是打算
如果你一定要赶上早班公交车,务必要在5点之前就起床.
如果说be going to do 也是一般现在时表将来的话,那就是语气要弱于be to do
be to do =must,be sure,语气很强
be going to do 的语气略微弱点,有推测口吻