Plastic bags are provided for our convenience but they have also_______ the pollution of the environment.
——Whose advice do you think I should take?——_________________________.
The Big Ben, _______ we visited during a recent trip to Britain, is one of London’s tourist attractions.
Now we could not do anything but _______ for him here.
Mr. Li will give us ________ talk. ________ talk will begin at 8:00.
Access _______ the factory is through a forest.