Everybody was too tired to stay on their feet．为什么要用on their

Everybody was too tired to stay on their feet．为什么要用on their stood on their own feet get back on their feet Everybody needs a shoulder to cry on sometimes in their on their way to. He was too tired to go on walking 同义句 He was too tired to go on reading.请翻译 He was too tired to work on.同义句 stay abroad on their own.Moreover,their parents may be on their He was so tired that he couldn't go on working.(用too...to... on their way to work