The students (do) _________ the project in Unit 10 now.

• do

• did

• is doing

• are doing

He (do) ______ his homework in the library now

• are doing

• does

• is doing

• did

We (look for) __________ a cheap, clean and effective source of energy now

• are looking

• looked

• looks

• is looking

I'm afraid I have no time to help just now. I (write) ______ an essay.

• write

• wrote

• is writing

• am writing

Look! The boy (run) ______ after the school bus.

• are running

• runs

• is running

• run

How many types of energy __________ (humans, use) at present?

• humans uses

• are humans using

• is humans using

• humans used

My father __________ (replace) the old bulbs in my room at the moment.

• replaced

• are replacing

• replaces

• is replacing

We __________ (discuss) about the advantages of some energy sources now.

• are discussing

• discussed

• is discussing

• discuss

He hasn't got a bike at the moment, so he (walk) ______ to school this week.

• walks

• are working

• is walking

• walked

Today, governments __________ (face) multiple challenges of energy security.

• faced

• are faced

• are facing

• is facing