It was she that a sharp whistle, which makes possible for us to catch the thief.
A. gave off; this
B. gave out; that
C. gave; it
D. sent out; them
网友回答
@@A. gave off; [email protected]@B. gave out; [email protected]@(答案)C. gave; [email protected]@D. sent out; them
解析：
前半句即主句是强调句，强调she；后半句是which引导的非限制生定语从句，it为形式宾语，指代真正的宾语即动词不定式短语to catch the thief.