题目

在DNA分子的一条链中，（G+C）/（A+T）＝9／11，那么其互补链中（G+C）/（A+T）的比例是 （ ） A.9／11    B.11／9    C.11／20    D.1 答案：A－I’ve decided to compete in the race, but I’m afraid I won’t be the best.－____. You never know until you try.A． Enjoy yourself B．Go for itC．Take it easy D．Take your time