It is a pity that the industrial cities _____ in the nineteenth century do not attract visitors.
Only after Mary read her article a second time _____the spelling mistakes.
--- Tom , why didn’t you answer my call yesterday afternoon?--- Sorry , I didn't hear the phone . I ___________ asleep.
If you want to change for a red one you'll have to pay ___________ $ 20.
September 18, 1937 is a day _______ all Chinese will remember forever.
There are some health problems that , when _______ in time , can become bigger ones later on.