It is a fact that traffic and pollution becomes the major problems to modern citescities.
traffic and pollution - two things.... therefore they are major problems : )
Some peoplethoughtthink thatthe dramatic increaseingin number of private cars every year is essential reason to cause such a problem and claim the best way to solve is to raising the price of petrol.
Some people think ,,,,, - you must keep this in present tense. "thought" is the past tense of "think"
The above sentence has many grammar errors;
Some people think that dramatic increase in the number of vehicles cause is the reason for this problem. They argue that the best way to solve this issue is to raise the price of petrol.Always try to have short sentences.... Lengthy ones try to get you carried away : )