Present Perfect or Past Simple tense1 He ___ (buy) a new cell phone yesterday.He ___ (use) it for two months2.Last year we ____ to Scotland for our holidays. (go)3 You look relaxed! Yes ,I ___ on vacation. (just been)4 I can't join you now because I ___ my homework yet.(not do) ​

1. bought; has used.
2. went.
3. have just been.
4. 've not done.