________ the houses were knocked down in the earthquake.

C. A great many of
辨析：
plenty of很多;大量,修饰可数、不可数名词都行.
There were plenty of eggs in the house.家里有许多鸡蛋.
a good many 只修饰可数名词,后面跟复数形式
a great deal of修饰不可数名词
many a 意思是“很多”,但后面要跟可数名词单数,是个固定搭配,
如： many a student很多学生
a good many 修饰可数名词
a great amount of, a great deal of 修饰不可数名词都表示“很多,大量”,good 和 great 可以互换,
如：a good deal of, a great many.
I hope I have a great amount of money and a good many knowledges.