a seal upon one's lips的用法和样例：
- They summed up all his previous existence, and in summing it up had put a seal upon it.
- Set me as a seal upon thine heart, as a seal upon thine arm: for love is strong as death; jealousy is cruel as the grave: the coals thereof are coals of fire, which hath a most vehement flame.
- I looked upon the gift as a seal on our friendship.
- Their handshake was a seal of friendship.
- Do you know how much a seal coat is?