一个圆锥的左视图是一个正三角形,则这个圆锥的侧面展开图的圆心角等于( )
A:60°
B:90°
C:120°
D:180°
—Yes. Some of them are good and the film Transformers: The Last Knight, is excellent.
下列哪类动物的主要特征是:身体呈两侧对称,背腹扁平,有口无肛门( )