You can only be sure of _____ you have at present;you cannot be sure of something _____ you might get in the future.
-- You are always full of _______. Can you tell me the secret? -- Taking plenty of exercise every day.
We held a party on Christmas Eve at a hall _______ with colourful balloons and flowers.
After the heavy snow, many students helped to clear away the snow ______ in our school.
We went through a period_______ communications were very difficult in the countryside.
Professor James will give us a lecture on the Western culture, but when and where _______ yet.