问一个弱弱的逻辑题GWD3-Q20,谢谢!

Shipping Clerk:  The five specially ordered shipments sent out last week were sent out on Thursday.  Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend.  Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.

If the shipping clerk’s statements are true, which of the following must also be true?

1. At least one of the shipments sent to Truax Construction last week was specially ordered.
2. At least one of last week’s specially ordered shipments did not consist of building supplies.
3. At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week.
4. At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction.
5. At least one of the shipments sent to Truax Construction last week was sent out before Friday.

这个题做的时候偶也纳闷了一下，按顺序看选项下来，觉得a、b都对么，后来看作最后的e，明白了，事情是这样的。题干中只提到了Thur and Fri，所以我就在潜意识里默认了上周只有这两天发货，说就把不满足fri的货的情况都归到周四，其实，这周不只这两天发货的，只不过题干只提到了这两天，所以应该是e中的before friday。

恩，偶的逻辑错误是这么找到的，不知道你是不是跟我疑惑在同一个点上。。。