The puppy stopped in front of him, and gave a sharp bark.
小狗在他面前停了下来，发出了尖厉的吠声。
2
Which way is the wind blowing? How many kinds of wildflowers can be seen from your front door? If your awareness is as sharp as it could be, you'll have no trouble answering these questions.
风往哪个方向吹?从你的前门可以看到多少种野花?如果你感觉足够敏锐，你就能毫不费力地回答这些问题。
3
All are keeping a sharp look-out in front, but none suspects that the danger may be creeping up from behind.