Pull yourself together and try and stand up straight.
打起精神，站直。
2
The feather must be removed with a straight, firm pull.
羽毛必须笔直地用力一拔才能拔掉。
《柯林斯英汉双解大词典》
3
If you took the sun away, it would be like cutting the string that provides the pull and in that case what you would see is that the planets would just take off along a straight line.