单选题 It has been proved that ______ up smoking and ______ more vegetable can help you to avoid cancer.
A. give; eat B. giving; eating C. gave; ate D. given; eaten

【正确答案】 B

【答案解析】[解析] 该题考查动名词词组作主语的用法。该句it为形式主语，真正主语为that引导的主语从句，即“giving up smoking and eating more vegetable”在从句中充当主语，故选B。