A. Complete each sentence with the correct word or phrase.
explore
submersible
mystery
give up
pioneered
1. A__________ is a vehicle designed for use underwater.
2. When I started playing the piano I was very bad but I didn't _________ Now I am quite good at it.
3. Scientists in Britain ______ cloning. A few years ago they cloned the first sheep Dolly.
4. Nobody knows how the pyramids in Egypt were built. It is a __________.
5. When you go to a new place it's fun to ____________.