动车组由哪8部分组成？
参考答案：
由车体、转向架、连接缓冲装臵、制动装臵、车内设备、牵引系统、辅助系统、网络系统。
Sir, you _______ be sitting in this waiting room. It's for women and children only. [ ]
A. oughtn't to
B. can't
C. won't
D. needn't
