题干
— Does Bob ______ a tennis ball?
— Yes, he ______.
A：has, does
B：have, does
C：has, do
D：have do
答案(点此获取答案解析）
B
— Does Bob ______ a tennis ball?
— Yes, he ______.
A：has, does
B：have, does
C：has, do
D：have do
（a、b分别代表不同的原子或原子团）互为同分异构体。据此推断一氯丙烯的同分异构体（不含环状结构）共有 （ ）