In our school library there a number of books on science and the number of them growing larger and larger.
A. is; are
B. are; is
C. is; is
D. are; are
网友回答
A. is; are
(答案→)B. are; is
C. is; is
D. are; are
解析：a number of一些，许多；the number of……的数目。句意：我们学校图书馆有许多有关科学的书籍，并且他们的数目变得越来越大。结合语境可知前文主语为复数形式，故系动词用复数。下文主语number表示抽象含义，故谓语动词用单数，选B。