____ his homework, the boy went out to play games with his friends.
The heart is believed to _____blood into veins(血管) which are netted all over the body, thus keeping a person alive.
______addition to being creative, perseverance and diligence are necessary qualities to be a good scientist.
The gold loop discovered in the ancient tomb _____ to be _____ in studying the history of the Jin Dynasty.
Every day Mother sets about her housework ______ she returns from work. Which of the following is NOT OK?
So ______ was he in his work that he didn’t notice that it was raining hard.