问题
问答题
如图所示,光源S发出的一条光线射向水面,在水面处发生反射和折射后,反射光线经过A点,水中的折射光线经过P点,请你作出入射光线、反射光线和折射光线.
答案
根据平面镜成像的规律,作出点光源S在平面镜中成的像S′,由于反射光线的反向延长线要过像点S′,连接AS′,其与水面的交点就是入射点O.
分别连接SO、OA、OP,可以确定入射光线、反射光线、折射光线.答案如下图所示.
如图所示,光源S发出的一条光线射向水面,在水面处发生反射和折射后,反射光线经过A点,水中的折射光线经过P点,请你作出入射光线、反射光线和折射光线.
根据平面镜成像的规律,作出点光源S在平面镜中成的像S′,由于反射光线的反向延长线要过像点S′,连接AS′,其与水面的交点就是入射点O.
分别连接SO、OA、OP,可以确定入射光线、反射光线、折射光线.答案如下图所示.
阅读理解。 | |||||||||||||||||||||||||
Sunny Language School We are a language school for children of 12-18. We want an assistant in the library, an English teacher, a gate- keeper, and a sports coach.
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1. Who can't go to Sunny Language School? | |||||||||||||||||||||||||
A. A 13 - year - old child B. A 17 - year - old child C. A 15 - year -old child D. A 20 - year -old child | |||||||||||||||||||||||||
2. Who is not wanted in the ad? | |||||||||||||||||||||||||
A. A waiter B. A teacher C. A sports coach D. A gate - keeper | |||||||||||||||||||||||||
3. Who doesn't need to speak English? | |||||||||||||||||||||||||
A. A teacher B. A lab assistant C. A sports coach D. A gate- keeper | |||||||||||||||||||||||||
4. The sports coach must(必须)______. | |||||||||||||||||||||||||
A. major in P.E. B. know two languages C. be healthy and strong D. All above | |||||||||||||||||||||||||
5. Who needs speak three languages? | |||||||||||||||||||||||||
A. A lab assistant B. A teacher C. A sports coach D. A gate - keeper |