能正确解释黑体辐射实验规律的是（   ）

下图是制作临时装片时的几个步骤，它们的先后顺序应该是（　　）

已知菱形周长为20，两对角线之比为4：3，则菱形面积为____．

DNA分子上的某个基因片段含有1800对碱基，由它控制合成的蛋白质分子最多含有的氨基酸数为（    ）

补全对话

A. We are going to see a film. B. Have a good time! C. When is her birthday? D. This is Chen Jie. E. What is Amy doing?

Mike: Hello.
Chen: Hello.____What are you doing?
Mike: I'm making a birthday card for my Grandma.
Chen:____
Mike: It's June 3rd. It's coming.
Chen: Happy birthday to her. ____
Mike: She is listening to music.
Chen: What are you going to do tomorrow?
Mike:____What about you?
Chen: I'm going to take a trip.
Mike:____
Chen: You too. I have to do my homework now. Bye.
Mike: OK. Bye.