In dry weather ,the flowers will have to be watered if they__

问题描述:

In dry weather ,the flowers will have to be watered if they__
A. have survived b. are to survive c. would survive d. will survive
为什么要用不定式呢 有点不明白 不定时也是表将来的一种呀状语从句一般都用一般现在表将来 ,这题为何不用 survive 原形呢 ?
为什么没有 survive 这项呢

b. are to survive
天气干旱时,如果想让花存活,就得给它们浇水.
be to do,表示目的,一种客观要求或计划安排,同时从形式上照顾了主将从现的要求.即使有survive这个选项,也应该选B,此句也可以简略为 in
dry weather ,(to survive,也可以放在这里,加逗号隔开)the flowers will have to be watered to
survive.