Open mouth of the pipe with a diameter of more than can use wooden wedge building control, can use sacks encase or more soft as a piece of polystyrene foam and other mouth.

• 敞开的下水管口可以使用直径大于关口的木楔子塞住，也可以用编织袋包住或用比较柔软的如聚苯泡沫等塞住管口。