1. Scientists are about to make a vital breakthrough.
=> Scientists are on...
2. It was assumed that Roy would marry that old rich lady.
=> People took ....
3. This course will take us 6 months to complete.
=> In 6 month times....

She began to play the piano 5 years ago

=> She has

It last snowed 2 weeks ago.

=> It hasn’t

This is the first time I have met him

=> I have

This is the most interesting novel I have ever read.

=> I have