【单选题】The air in big cities _____very dirty by factories.
【单选题】Do you know the student____________?
【多选题】设计思维创新实践流程的步骤五介绍了三个关键概念,分别是()。
【单选题】Turn on the television or open a magazine and you ________ advertisements showing happy families. A. will often see B. often see C. are often seeing D. have often seen
【判断题】可编程逻辑器件的逻辑功能是用户通过对器件编程进行设定的。
【判断题】在汉字产生之前,人们为了帮助记忆、交流思想、传递信息,采用的最原始的记录方法是图画记事。