The cars in the 1920s were much slower than those of today, but they ________ run faster than a bike．
A.wouldB.didC.hadD.have在线课程B
本题考查助动词do用于加强语气的用法。do用于祈使句和陈述句中加强谓语动词的语气。如：He does work hard．I did go to the cinema．Do be careful．本句的句意是：20年代的车是比现在的车慢多了，但比起自行车来的确是快多了。所以答案为B项。