—Have you found the missing?couple in the mountain ? —No, but we hard to get in touch with them.
The word "breakthrough" is often used when talking about the newest drug or the next treatment ___ in cancer research.
October 24, 1860, the Qing government and the Britain sighed "the treaty ofBeijing", ___ put an end to the second Opium war.
___ the invention of the steam engine, the industrial revolution played a vital role in human history.
Blog, a shared on line journal where people can post diary entries about their personal experience and hobbies, ___ more and more popular with people of all ages.
My car’s performance is ___ since the engine’s been tuned and the tires have been changed.