Recently, I saw an interesting question: several cups are connected together with pipes, and ask which one is filled with water first. There was a quarrel in the comment area, some people said No. 1, some people insisted on No. 7, and some people bet on No. 3, and they almost quarreled.

Looking at the structure, the No.

1 cup has two outlets, the left side is connected to No. 2, and the right side is connected to No. 3. However, the right interface is lower, and the water flows to the lower place, so the water from No. 1 preferentially flows into No. 3, and No. 2 on the left is temporarily out of water.

Looking at cup 3 again, it connects No. 6 and No. 7, and the interface to No.

7 is lower, and the water flows into No. 7 first. Moreover, the inlet pipe interfaces of No. 4, No. 5 and No. 6 are higher than the mouth of the cup, and the water cannot flow in.

The No. 7 cup does not have a water pipe, and the water is stored when it is poured in, so it is naturally the first to be filled.

It's like a sink at home, where the water always goes to the low drain. Don't stumble when you encounter a problem, look for the key details (channel level, whether it is blocked), and the answer will be clear. The troubles in life are like this, sort out the order, and no matter how messy it is, it can be solved~

(Answer: The No. 7 cup is filled first, the key is to see "the water flows to a low place" and "whether the pipe is open", it's simple!) ）