A. Both healthy and unhealthy groups have increased blood pressure.
B. Both healthy and unhealthy group has increased blood pressure.
C. Both healthy group and unhealthy group have increased blood pressure.
我觉得C应该一定对
但不知道A跟B到底哪个才正确？
因为两个好像都有看过
Thanks

A

A

A，两者皆是，动词用复数。如果是either or,neithernor,not only but also句型才是动词跟某个主词变化

C is wrong.

A

C哪里wrong?

C的第一个group 会变成是冗词赘字，文法上其实也没特别太大的错误。