Past simple or present perfect?

Since the forest fire, we ________ about climate change at school.

• talked

• have talked

Our government ___________ the use of plastic bottles yet.

• didn't ban

• hasn't banned

I ________ about the use of fossil fuels last year.

• read

• have read

_________ Bruno Mars perform?

• Did you ever see

• Have you ever seen

He ___________ (never/speak) to environmental activists.

We _________ (watch) an interesting wildlife programme last night.

Our class _______ (not learn) about recycling yet.

My friends __________ (not go) to the concert last weekend.

These floods ______(already / cause) many problems.

My friends ______________ to a demonstration last week.

• went

• have gone