1. Students in Class One will act as guinea pigs among the new teaching reform.
一班的学生将充当本次新课改的实验对象。
guinea pigs:受试者，实验对象

2. Handmade lace is as rare as hen's teeth; most lace is made by machine.
手工制作的蕾丝极为罕见，大部分是机器做的。
hen's teeth:极为罕见

3. Don't mention anything about that to your father. It's like a red rag to a bull.
不要在你爸面前提起那件事。他听了肯定会生气的。
a red rag to a bull:让某人生气的人或事

4. If you say that to her, you will be stirring up a hornet's nest.
如果你把那件事告诉她，那简直就无异于捅了马蜂窝。

5. I thought he was going to have a cow when I told him I'd lost his key.
当我告诉他我丢了钥匙时，我以为他会大发雷霆的。
Have a cow:大发雷霆

6. He was like a cat in hot bricks before his driving test.
驾驶考试之前，他紧张得像热锅上的蚂蚁。
like a cat in hot bricks:热锅上的蚂蚁