I repeatedly beat the eggs for thirty minutes
He slept for two hours
She queued up for a day to get that
for + 时间 = 花了/用了多少时间在一件事上那不加for捏？How long did you take to complete the project? I took two hours/ How long have you ....通常回答是　for+时间 如　how long have you two been dating? We have been dating for two years? How long have you been studying? I have been studying for two years.