поставте в подходящую форму слова в скобках, используя времена:Present simple,present

Поставте в нужную форму слова в скобках, используя времена:Present simple,present continuous,.past simple,past continuous or present perfect.
1)John (trip) and (cut) his knee as he (walk) up the volcano.
2)Martin (not/reach) the crater yet.
3)Look at the volcano.Huge rocks (explode) out of the crater.
4)they (go) volcano surfing tomorrow.
5)Luke (work) hard for the last three weeks.
6)We (leave) for Chile next Monday.
Помогите,буду благодарна)