a number of后可直接加具体数字吗?a nunber of 40,000 per year.

a number of后面可加不可数名词吗 A number of后能不能加不可数名词 a number of后加可数名词复数还是单数 a large number of后加复数么? Number of photons per a large number of ,a large amount of ,huge amount of后加可数还是不可 average number of paid vacation days per year 翻译汉语 number of school days per year翻译汉语 a number of前加be动词加啥子?the number of后加be动词加啥子? a bit of,a gread deal of,a number ofand(a) plenty of后加的名词是可数 a bit of,a gread deal of,a number ofand(a) plenty of后加的名次可数还 a number of 可以加不可数名词吗?