each time Caroline turns on her computer,she <has> to enter a company code, then her initials, and then <enters a password><before>she can< begin working>. <no erroing>
答案说第二个括号是错的,但我不知道为什么
Delgado's dilemma was <like many other> young writers: he <had to choose> between assured publication in a student magazine <and> <probable rejection by> a popular magazine
答案是第一个错的。。我也不理解。。
air polution caused by industrial fumes< has been studied> for years, < but> only recently <has> the harmful effects of noise pollution <become> known.
答案是第三个。。不理解。。。抱歉
请求帮助,谢谢
抱歉。关于第一个。。。我要是修正它的话。。我该写成“TO ENTER”还是就“ENTER”?