_____to nuclear radiation, even for a short time , may produce variants(变异体) of genes in human bodies.
| A．Being exposed | B．Having expose |
| C．Exposed | D．After being exposed |
Edward, you play so well, but I _____ you play the piano.
| A．didn’t know | B．hadn’t known | C．don’t know | D．haven’t known |
She’ll never forget her stay there ______ she found her son who had gone missing two years before.
| A．that | B．which | C．where | D．when |
Jane has been so ______ in getting used to everything that she hasn’t had time for social activities.
| A．occupied | B．confused | C．devoted | D．worried |
Though trying really hard, they acknowledged ____ at last.
| A．defeated | B．defeating | C．having defeated | D．having been defeated |
---Guess what? We’ve got our visas for a short-term visit to the UK this summer.
---How nice! You ____ a different culture then.
| A．experience | B．are experiencing |
| C．will be experiencing | D．have been experiencing |