A:30°
B:120°
C:60°
D:150°
—Has Jack finished painting the picture yet?—I've no idea. But he______ it the whole afternoon.
一个角的度数比较小,只有3°,为了看清楚些,用一放大倍数为5倍的放大镜观察,可以看到这个角的度数为: