present perfect simple vs continuous

I've ... for you for an hour!

• been looking

• looked

How many paintings have you ...?

• been selling

• sold

We have ... for a couple of weeks now.

• been travelling

• travelle

The professor has ... more than 100 questions about the Louvre.

• answered

• been answering

John has ... Cynthia since primary school.

• been knowing

• known

I've ... most of his paintings.

• been seeing

• seen

How long have you ...?

• been waiting

• waited

Have you ... your essay all morning?

• been writing

• written

How many art galleries has ... today?

• been visiting

• visited

How long have you ... this painting by van Gogh?

• been having

• had