_____the beginning of the 19th century did scientists know that all matter is made up of atoms.A,At B,By C,Up to D,Not until
— Tom, what a pity! I almost succeeded yesterday. —_______. I told you to be careful before.
A local publicity official said a trampling accident happened at a private school in Xiangtan city, Hunan Province, _______ eight dead and twenty-six _______.
— Mum, I really think Dad should have a break and get relaxed. — Yes. He _______ too long.
Barack Obama delivered a speech to 500 local youths during his visit to China, many of _______ were from Fudan University and Tongji University.
_______ his grades with Arnold’s, George was quite satisfied.