我需要帮助弄清楚为什么我翻转功能只触发一次，他们似乎解开。什么好主意吗？

I need help figuring out why my flip function only fires once and them seems to unbind. Any ideas?

youdao

要是看见有只印了一面的纸，我一定会把它翻转过来再印一次。 大家也都知道我这样的脾气。

This correspondent has always believed in printing on both sides of paper and has been known to put paper printed on just one side back into the office printer, upside down.

youdao