【题目】The doctor advises us to exercise ________ on hazy (雾霾) days because it may influence our health.
A.more
B.less
C.better

【答案】B
【解析】句意：医生建议我们在雾霾天少锻炼因为雾霾会影响健康。根据句意和常识可知，雾霾天少锻炼，故选B。