【单选题】It can repair your cells.
【单选题】---- I’m so sorry that I made your computer stop working. ---- _______. I can repair it myself.
【单选题】— You can repair your bike. It's not broken enough, Jack. — I'd rather ________ a new bike than ________ it. [ ]
【单选题】— Tom, I made your computer system break down. I will pay someone to repair it. — Oh. ______. I can solve it by myself.
【单选题】It can be cheaper to buy a new washing machine than to get your old one _____.
【简答题】常用蜗杆的头数为____头,用于 自锁作用的蜗杆应选用____头。
【简答题】常用蜗杆的头数为( ),用于自锁作用的蜗杆应选用( )头。
【判断题】根据比较优势理论,如果美国生产牛肉的机会成本高于阿根廷,则应有阿根廷出口牛肉