=>
1. It is so tiring to travel on road in rush hours because of traffic jams.
-> it is (so/very) adj to V
-> because of N/Ving : bởi vì
2.  Yesterday, it took my mother more than an hour to go to her office.
-> yesterday (QKĐ, S V2/ed)
-> take/took sb time to V
3. Travelling from Hanoi to Ho Chi Minh city by airplane is not time-consuming.
-> from...to : từ...đến
4. The team spent more than three months completing this project.
-> spend time Ving ~ take sb time to V
5. It often costs a visitor only 50.000 VND to buy an entrance ticket.
-> often (HTĐ, S Vs/es)