HE SPENT TWO HOURS ______________ THE WAY TO OPERATE THIS CELL PHO...

220. - 300 CAU TRAC NGHIEM HOC KY II KHOI 10
300 CAU TRAC NGHIEM HOC KY II KHOI 10
220.He spent two hours ______________ the way to operate this cell phone.a. is going to rain b. will rain c. is raining a. to discover b. discovering c. discover d. to be discovered