Put the verbs in brackets in present simple, present continuous, past simple, past continuous or present perfect. Give reasons. 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. 7 People ..... (look) at the volcano as lava ..... (flow) down during the eruption last night.

Reason: 'Tripped' and 'cut' are in the past simple because they are completed actions in the past. 'Was walking' is in the past continuous because it describes an action in progress in the past when another action happened.

Reason: 'Hasn't reached' is in the present perfect because it describes an action that started in the past and continues to the present, indicated by 'yet'.

Reason: 'Are exploding' is in the present continuous because it describes an action happening right now.

Reason: 'Are going' is in the present continuous used to express a future arrangement.

Reason: 'Has worked' is in the present perfect because it describes an action that started in the past and continues to have relevance in the present, indicated by 'for the last three weeks'.

Reason: 'Are leaving' is in the present continuous used to indicate a future arrangement or plan.

Reason: 'Were looking' and 'was flowing' are both in the past continuous to describe actions that were in progress simultaneously in the past.