问题
选择题
They made up their mind that they______ a new house once Larry changed jobs.
A．bought
B．would buy
C．have bought
D．had bought
答案
答案：B
题目分析：once引导的是条件状语从句，根据主句将来时从句一般现在时的用法可知，从句一般过去时，主句应是一般将来时的过去时。句意为：他们打算只要Larry换了工作他们就买新房子。故答案选B。
的氧化性依次减弱