`15.` It took them their whole week to identify the problem in the production line.

`16.` It took Nam lots of time to do this experiment.

`17.` Huy spent all morning preparing for lunch.

`18.` It took John three days to visit VN.

`19.` My son spent three years studying at this college.

`20.` It takes Trung two hours to do his homework every day.

`----------------------`

`-` Cấu trúc: It `+` take (chia thì) `+` sb `+` to do sth

`=` S `+` spend (chia thì) `+` time `+` doing sth

`->` Ai đó mất/dành thời gian làm gì ...

`15,` It took them their whole week to identify the problem in the production line

`16,` It took Nam lots of time to do this experiment

`17,` Huy spent all morning preparing for lunch

`18,` It took John three days to visit VN

`19,` My son spent three years studying at this college

`20,` It takes Trung two hours to do his homework every day

___________________________________________

`@` S + takes/took + O + t/gian + to Vbare-inf ...

`=` S + spend(s)/spent + t/gian + V-ing ...