The train ______ when I ______ to the station.
How much time did you spend the new words in Unit 10?
Since June 1 2008,all the markets have_________free plastic bags.
---Have you seen Dr. Adams recently?---No. He __________ Hong Kong for an important meeting. He’ll come back tomorrow.
-- Has your sister come back? --Yes, she has. She______ back two days ago.
There __________great changes in our hometown in the past fifteen years.