试题题干
It was not until he had lost his health（ ）he got to know its value.
参考答案
正确答案：
试题解析
去掉it was及空缺处连词后，句意依然完整，故本句符合强调句结构：It is/was+(被强调部分)+that+句子剩余部分，被强调部分为时间状语“not until he had lost his health”，C选项符合题意。
句意：直到他失去了健康，他才开始明白它的价值。