Writing Feedback / Improving people's health by cleaning the environment. TOEFL writing [4]

In my opinion is more common
there are some factories producing polluted water ..., if people drink contaminated water, they maybe get sick and be unhealthier, people maybe ...

Writing Feedback / Hard Work vs Luck - what determines people's success? [5]

I think you should mention to use present continuous perfect tense : My brother has been making great efforts for the better part of 10 years