The development of industry has been_______ gradual process throughout _______ human existence, from stone tools to modern technology.
On Jan. 24 , 2012 ,Shen Zhou VIII returned to ____ earth from____ space successfully.
Sister Lotus came back home yesterday, ________, she was gone for years.
Han Han's novel was eventually ______as a work of genius.
We haven't got enough books for everyone; some of you will have to _______.
We all know that our teachers have different _______of teaching