1. Early next morning, she heard planes passing overhead and wondered how she could send a signal.
    第二天清晨，她听到头上有飞机飞过，却不知道怎样才能发出信号，

2. Early next morning, she heard planes passing overhead and wondered how she could send a signal.
    第二天一大早，她听到头顶上有飞机飞过，但不知道怎样才能发个信号。

3. But we are the ones who signal to businesses that what they are doing is okay — every time we buy their products.
    每当我们购买他们的产品时，我们就在向企业发出信号，告诉他们可以这样做。

4. For there was a danger that if she travelled too quickly, this rudder would be torn away as well.
    因为船不能开得太快，否则就有危险，应急舵也会被刮走。

5. Was it the signal?
    这是那信号吗?

6. The soldiers lay in ambush, waiting for the signal to open fire.
    士兵布下伏兵，等待开火的信号。

7. The irregularities in depth of the shallow water close to the land bring danger to trip.
    靠近陆地的浅水区深浅不一给航行带来了危险.

8. The crowd began to shout, but the matador was unaware of the danger.
    观众大哗，但斗牛士却没有意识到危险。

9. The crowd began to shout, but the drunk was unaware of the danger.
    观众大哗，但醉汉却没有意识到危险。

10. There was a danger that the wave would rebound off the other side of the bank and send the dish plunging into the water again.
    但是当波浪从河对岸折回来时，就有再次把盘子拖进水里的危险。