一种油的密度为ρ,摩尔质量为M。取体积为V的油慢慢滴出,可滴n滴。将其中一滴滴在广阔水面上形成面积为S的单分子油膜,阿伏加德罗常数是______________。
Although his father is quite busy, he the newspapers when he eats breakfast. [ ]
A. looks at
B. reads about
C. looks through
D. prints
生态工业是一种循环经济发展模式,其发展模式是()。
A.资源-产品-废物
B.资源-废物
C.资源-产品-再生资源-再生产品
D.资源-产品-再生资源-再生产品-废物