Bythe1850sNoahWebster’sfirstbookwassellingonemillionc...

问题详情：

  By the 1850s Noah Webster’s first book was selling one million copies a year , ____ it one of the most popular school books ever .

A. make              B. made                C.  making                D.  to make

【回答】

C

知识点：非谓语动词

题型：选择题