In less than a minute, it roared past them only a few feet away. After it had passed, they swam on as quickly as they could because they knew that the boat would soon return. They had just had enough time to swim out of danger when the boat again completed a circle.

21'

译文：
不到1分钟的功夫，他从离他们只有几英尺远的地方呼啸着驶了过去。快艇过去之后，他们以最快的速度向前游去，因为他们知道快递马上就要转回来。他们刚刚来得及游出危险区，快艇又转完了一圈。