New medicines and instruments ______ every day to extend life.
Let’s learn to use the problem we are facing ______ a stepping-stone to future success.
The performance ______ nearly three hours, but few people left the theatre early.
—What fruit is in season now?—Grapes and peaches, ______.
—Would you like to join me for a quick lunch before class? —______, but I promised Nancy to go out with her.
We ______ last night, but we went to the concert instead.