[讨论]800score里的一题

Every store on Main Street in Summitville has an awning, and all of these awnings are either green or red. If the statement above is true, which one of the following must also be true?

I. Some awnings in Summitville are green.

II. If a store in Summitville does not have an awning, then it is not on Main Street.

III. If a store in Summitville has a red awning, then it is on Main Street.

A) I only

B) II only

C) I and II only

D) I and III only

E) I, II, and III

先不说答案,看大家选什么

C

B

I.错。因Sumnitville中的awnings可以都为red。（either..or..）

2.对。原文的逆否命题

3。错。原文的逆命题