Ra是光源特性指标中的（）。
A.色温
B.显色指数
C.光效
D.频闪
参考答案：B
看图填空。
Do you know what a snowman is? We make snowmen in China. First we make a big ball of 1__________ . Then we make another small 2__________. We put the smaller one on the top. Let's make 3__________ on the snowman. This 4__________ is his 5__________. I have some little
rocks for his 6__________ and 7__________. I have two 8__________ for his
9__________.
蛇串疮的中医命名中其中有一个是：
A．湿疮B．热疮C．脓疱疮D．蜘蛛疮E．天疱疮
. Then we make another small 
2__________. We put the smaller one on the top. Let's make 
3__________ on the snowman. This 
4__________ is his 
5__________. I have some little 
6__________ and 
7__________. I have two 
8__________ for his