Volunteers in national science museum go through three months of study, training and discussion with experts before ( ) to talk in public.

(单选题)-I should have gone to see the film with you. - ( ). (单选题)- ( ) have you been in Guilin?-Three weeks. (单选题)Eating better and eating less could be the ( ) not only t (单选题)So you have to leave. How nice it ( ) if you ( ) a bit (单选题)Don’t forget the day ( ) you were received into the Youth (单选题)-This dress was last year’s style.-I think it still looks pe (单选题)Don’t all speak at once! ( ), please. (单选题)Family education has a great ( ) on children in many ways (单选题)The prisoner of war wished to be ( ).Ten years later, he (单选题)This digital camera is really cheap! The ( ) the better.