如图所示,是光在空气和玻璃两种介质中传播的情形,下列说法正确的是
A.入射角等于30°
B.折射角等于50°
C.NN'是界面
D.MM'的右边是玻璃
答案:D
.
Will you spare me a few minutes now?
_______. But I’ll be free in half an hour.
A.Yes, of course
B.No. I can’t
C.Yes, with pleasure.
D.I’m afraid not
肾脏激素包括()
A.肾素
B.红细胞生成素
C.胰舒血管素
D.前列腺素
E.类固醇激素