It was she went back home Kate realised she had left her schoolbag at school.
A. when; then
B. not; until
C. only; when
D. not until; that
网友回答
A. when; then
B. not; until
C. only; when
(答案→)D. not until; that
解析：句意：直到她回到家。凯特才意识到她把落在学校里了。until在强调句式中要把not放在until之前；在强调句式中除了强调人可以用who外，其他的情况一律用It is /was...that...。故选D。
考点: 考查not until的强调句式的用法。