选择:A on condition that
They agree to rent the house on condition that the roof be repaird.只要将房顶修好,他们同意租用房子.
on condition that 引出条件状语从句,意思是:“以什么为条件”、“只要……”,可以引导虚拟条件句,这时动词用原形,正如本句话中的 the roof be repaird 中的be.而as soon as...是:“一...就...”,引导时间状语从句,"他们同意租用房子" 是将来的事,而在表示将来的时间状语从句中用一般现在时,所以如果选择 as soon as ,句子后半句应该是:the roof is repaird ,但是句子中用的是:the roof be repaird 而不是 the roof is repaird ,所以选择A.