Question

【题目】Helen volunteers once a week _______ in an old people's home.
A.work
B.works
C.worked
D.to work

Answer 1

【答案】D
【解析】句意：海伦在一个敬老院每周志愿……一次。volunteer to do志愿做某事，此处是指志愿工作，故选D。