12. ----- Why don’t you do some shopping in the second-hand store ? ------ Well, the goods there are _____, but _____.
.While building a tunnel through the mountain, ________ .
The train ________ arrive at 11∶30, but was an hour late.
.The two ladies are ________ the same age, but there seems to be ten years ________ them.
Paper produced every year is ________ the world's production of vehicles.
We have done things we ought not to have done and ______ undone things we ought to have done.