— Beijing is well worth visiting. I _____ there with my parents during the holidays.— I agree. I have been there twice.
Believe it or not, crying is a way you can imagine ______ pressure.
__________ the students who have taken part in the sports game is unknown.
_______, the more exercise you do, the richer your knowledge will be.
His mother happened _______ when his program was shown on Channel Young.
By the time he was ten, Edison _________ experiments in chemistry.