问题
选择题
The leaves are _________ the tree. The flowers are _________ it.[ ]
A. in, under
B. on, under
C. at, on
D. at, to
答案
答案：B
搜题请搜索小程序“爱下问搜题”
The leaves are _________ the tree. The flowers are _________ it.[ ]
A. in, under
B. on, under
C. at, on
D. at, to
答案：B
，球表面积公式是S球= 4πr2，圆面积公式是S圆=πr2，水的密度为ρ，为满足水位高度自动控制的要求，塞子的质量应为_____________。