光谱分析首先将试样(),然后再分光进行定性或定量分析。
A、蒸发、激发
B、雾化、离子化
C、分子化
D、雾化
参考答案:A
阅读短文,选择正确答案。
This is a picture of Mr. Brown's family. In the picture we can see Mr. Brown is sitting on a sofa. He is
reading the newspaper. Mrs. Brown is sitting near the computer. She is sending an e-mail to her mother. Mike
is 10 years old. He is a pupil. He is watching TV. Alice is 5 years old. She is playing with toys on the floor.
1. This is a picture of _____________.
A. Mr. Green's family
B. Mr. Brown's family
2. Where is Mr. Brown?
A. He is in the park.
B. He is sitting on a sofa.
3. What is Mr. Brown doing?
A. He is playing chess.
B. He is reading the newspaper.
4. Is Mrs. Brown sitting near the computer?
A. Yes, she is.
B. No, she isn't.
5. How old is Mike?
A. He is 9 years old.
B. He is 10 years old.
在某商店内,一位身高为1.6m的同学走到竖直放置的平面镜前3m处时,他在平面镜中的像与他的距离为 __________;当他走到距该平面镜6m处时,他在平面镜中的像的高度为__________。