Since June 1 2008，all the markets have_________free plastic bags．
| A．to stop to provide | B．to stop providing |
| C．stopped to provide | D．stopped providing |
---Have you seen Dr. Adams recently?
---No. He __________ Hong Kong for an important meeting. He’ll come back tomorrow.
| A．has gone in | B．has been in |
| C．has gone to | D．has been to |
-- Has your sister come back? --Yes, she has. She______ back two days ago.
| A．came | B．has came |
| C．has come | D．has been |
There __________great changes in our hometown in the past fifteen years.
| A．has been | B．have been |
| C．was | D．were |
-----________did your uncle leave his home town ?
----He ___________for nearly twenty years.
| A．When , has left | B． When , has been away |
| C．How long , has left | D．How long , has been away |