每个选项都解释下
问题描述：
每个选项都解释下
It is believed that basketabll ,________on December 21st,1891,was invented by a Canadian doctor.
A.first played B.first playing
C.was first played D.was first playing
答
1.答案：A.
2.翻译：据认为,在1891年12月21日最先被开玩的篮球,是由一个加拿大的医生/博士发明的.
3.
1）此题的中间插入的________on December 21st,1891其实是主语从句中的主语basketball的后置定语,并采用了动词play的非谓语形式.
was invented by a Canadian doctor才是紧跟basketball,并形成该主语从句的主*分.
2）被修饰词basketball和非谓语动词play之间的关系是被动的（篮球是被打/玩的）,所以用其过去分词形式played,first只是个状语.