He did very badly on the exam. He ___harder.A.must study B.must have studied C.should study D.should have studied本题答案选D，AC为什么错误呢，不能表示之后他必须或者应该好好学习吗？肯请老师解答，感谢！
In Washington, families letting Congress knowit's time to reconcile their differences. 在华盛顿，一些家庭表示他们要让国会知道，国会内部该调和分歧了。【疑问】1，为什么没有be动词？2，这个出自voa，所以我想问一下voa, bbc等到底是有...
请问 agreeable和pleasant的含义都是 “令人愉快的“ 或”宜人“ 含义时，它们的意思和用法有什么区别？例如： 1. They spend an agreeable/pleasant evening together.2. What a agreeable/pleasant surprise.3.It's a agreeable/pleasant environment to work in.
generous 通常用于 It is generous of sb to do sth。如：
It was generous of you to give us so much money. 你给我们这么多钱，真慷慨。
但是可以用于 sb is generous to do sth吗？比如下面这样改一下：
You were generous to give us so much money. 你给我们这...
请教老师以下句子：For us this has been the most perfect way to remember her, and this is how she would want to be remembered.这里的完成时如何理解？如果是表状态延续到现在为何没有时间状语？这个完成时也不是表示事件或习惯吧？
He first told police his son disappeared while the family was picking vegetables.请问 while 从句是修饰 disappeared 还是 told？如果修饰disappear 如何 改为修饰 told?如果修饰told 如何改为修饰 disappear？
It is important to figure out exactly what you want to tell the audience and what you are trying to get them to do.to figure out exactly后面两个并列的what从句是宾语从句吗？