straighten up phrasal verbphr v a) STANDto make your back straight, or to stand up straight after bending down 挺直身子，直起身来 He remained bent over for several seconds before slowly straightening up. 他保持弯腰姿势数秒，然后慢慢直起身来。
b) straighten something ↔ upTIDY to make something tidy 使整洁
c) American EnglishAmEBEHAVE to begin to behave well after behaving badly 变好，改好 You’d better straighten up, young lady! 小姑娘，你该学学好了！
straighten up• If you're lifting something heavy, be careful not to hurt your back when you straighten up.• You'd better straighten up or you'll never make it out of high school.• She bent over the body, and when she straightened up there were tears in her eyes.
→ straighten up at straighten(2)