Question

【题目】The chemistry teacher required the students ________ more attention _______ the lab clean.
A.to pay; to keep
B.to paying; to keeping
C.to pay; to keeping
D.paying; keeping

Answer 1

【答案】C
【解析】句意：化学老师要求学生注意保持实验室干净。require sb to do sth要求某人做某事。pay attention to doing sth注意做某事。故选C。