C

试题分析：考查谓语单复数，由主语quantities of apples是复数，所以排除B、D，a number of意思“许多”， a quantity of意思“大量的”，句子意思“篮子里有许多苹果，桶里有大量的牛奶”
点评：考查谓语单复数是常考内容，要求学生做此类题时，首先知道主语是单数还是复数，由主语单复数来确定谓语的单复数
即学即练：Every student as well as teachers who_______ to visit the museum ______ asked to be at the school gate on time.
A. is; is      B. are; are     C. is; are      D. are; is
选D