（）铁路信号表示按规定的速度运行。
A.蓝色
B.红色
C.黄色
D.绿色
参考答案：D
About 187 passengers were reported _____ the shipwreck which happened last month.
A．to have been survived
B．having survived
C．to have survived
D．to survive
后生包裹体
