1.It was brave of him to tell her what he thought about her.
2.I'm sorry to hear your bad news.
3.The number of people using public transport has dropped slightly.
4. I'm busy revising for exams at the moment.
5.The government decided to invest in building the very first metro systems as there was an increased demand for travel.
6.If I knewabout historical events, I could help her with her history homework.
7.I have never heard about the tram system in Hanoi before.
8.It takes firefighters 2 hours to releasing the driver from the wreckage.
9.The president was taken to the hospital an emergency operation.
10.After the computer crashed I had saved my document.
Hãy giúp mọi người biết câu trả lời này thế nào?