12.  Mrs Lien is very smart. I met the son of her on the stage last night.

……Mrs Lien, whose som I met on the stage last night is very smart..………………………………………………………………………………………………
13.  Dolphins are sometimes caught and killed in fishing nets. They often swim with other fish.

………Dolphins, which often swim with other fish, are sometimes caught and killed in fishing nets..……………………………………………………………………………………………
14.      The tourists visited China. They went to see the Great Wall and the old Kingdom in Beijing.

……… The tourists who went to see the Great Wall and the old Kingdom in Beijing visited China. .……………………………………………………………………………………………