A study ________ in the U.S.A. in 1977 showed that the chemical ASA in aspirin could prevent a stroke. A. carrying out B. carried out C. working out D. worked out
After months of voyage, Columbus arrived in _______ later proved a new continent.
______ needs further discussion to decide whether we will _______ the war operation.
Actually, girls can be _______ they want to be just like boys, whether it is a pilot, an astronaut, or a general manager.
_______ he met with the difficulty did he realize the importance of our help.
—Why do you drink so much coffee? —Well, _______ it doesn’t keep me awake in the night, I see no harm in it.