Question

Everything has changed ______ the last summer.​

Answer 1

Answer: the correct answer is ;:- during

Explanation:

Hope it helps you

Answer 2

ANSWER:

Everything has changed since the last summer.

EXPLANATION:

     The sentence talks about the event happening in the past. So it describes about the event happened in last summer. It describe last year whatever was there now it is not there. So we can make use of word since which describes about the event happened in last summer.

     Hence since is correct word which fits in the sentence. Since is used to indicate the event happened in the past to till date or time.