1.The old building in the city that is of high quality _________.
A. was sold at a cheap price 
B. were sold at a cheap price
C. was sold at a low price D. were sold at a low price
【答案及总结】C
句意：城市里的这个老建筑质量很好，可是以一个较低的价格出售了。这里要注意，不能选A，和price搭配的只能是高低，不能用cheap， 也不能用expensive。而B和D选项，be动词搭配错误，主语是building，是单数的概念。
