Question

        cycling is a fantastic way to burn a few calories and save some money, there still exist risks．

A．Since

B．While

C．As

D．When

Answer 1

B

试题分析：此处Since 自从；While 尽管；As因为；When当……的时候。句意：尽管骑自行车是燃烧热量的奇妙的方法，但也存在风险。根据句意选B。