If you want to fill a sink or bathtub with water, you need to do one thing first and that's stopper or plug up the drainpipe. Later, when you unplug the stopper, the used water will go rushing out down the drain. Hopefully, nothing valuable (such as a diamond ring) will be in that water, because after the water flows down the drain, it is gone forever. Anything that was mistakenly dropped into the water will therefore also disappear down the drain, and then it will be very difficult-probably impossible-to get it back.
注:本文译文属可可英语原创,未经允许,请勿转载。