左右车轮制动器制动力矩不平衡，左右车轮制动器操纵力不平衡易导致（）。
A.制动失效
B.制动跑偏
C.制动拖滞
参考答案：B
We on it for several hours but we haven't yet reached any conclusion.
A．are working
B．work
C．have been worked
D．have been working
大肠杆菌DNA聚合酶工具有的5’→3’外切酶活性也可以以RNA为底物。（）
