单词back-of-one-s-hand
Pressing one"s palms together and resting one"s head on the back of one"s hand while closing the eyes as if sleeping means "I am tired" .
双手合十，把头贴在手背上，同时闭上双眼好像睡着的样子，意思是“我累了”。
know somewhere like the back of one"s hand;
对一个地方了如直掌，是