圆锥的侧面积恰好等于其底面积的2倍，则该圆锥的侧面展开图所对应的扇形圆心角的度数为（ ）．
180°
被称为地球上“肺”的是 。
He moved away from his parents, and missed them（）to enjoy the exciting life in New York.
A. too much
B. very much
C. enough
D. so much as
