jawaban bahasa inggris hal 171 kelas 9

2) because they don't cross the road carefully or because they walk too close to the traffic
3) because on the roads
4) because there are traffic jams everywhere
5) because he thinks walking is healthy
6) because his father goes to his office by bike
7) because her father also rides on his bicycle to work
8) because more and more people drive or ride on their motorcycle to work or to school
9) because the air is dirty
10) because the air in big cities is polluted by the smoke from motor vehicles
11) because the sky is very clear there