下列说法正确的是（　　）

A．任何情况下，紫外线的照射对人体都是有利的

B．实验表明，红光的热效应最显著

C．不透明物体的颜色由照射光的颜色决定

D．电视机的遥控器可以发出不同的红外线，来实现电视机的遥控

用括号内单词的适当形式填空

1. This is my ______ (old)sister. She's one year ______ (old)than me.

2. If you want to be healthier and ______ (thin), you should eat less meat and take _____ (much)

exercise.

3. They were very happy throughout their _______ (marry)life.

4. That boy is the second _______ (tall)boy in our school.

5. Our town had ______ (little)snow this year than last year.