Question

【题目】The sons and daughters said they never fully appreciated their parents _________ it was too late to tell them.

A. as B. that

C. until D. When

Answer 1

【答案】C

【解析】句意:那些做儿女的曾说过：直到他们的父母无法知道他们非常感谢父母的养育之恩时他们才真正知道感谢他们。题干中的never与后面的until构成" not/never. . . until " 结构。