Happiness comes from your heart and your naturally feeling .it doesn’t follow(is not following) by living standard increased(increaing), then they told us those four typical characteristics. I f the (去THE)people have these characteristic(characteristics), they always(be) happy and they can keep the balanced heart. That’s very important. They believed themselves better than others. They can find happiness for themselves. So they support(hold on) the pressure and solve the problem .at last the pressure is digested by them .I think we should need this ability and control ourselves. We need give up something for(of) studying. (why we need to do that? you mean togive some ability up selectively?)
The meaning of extroverted that (is)the person (who is)more interested in what is(去掉ＩＳ) happening around him than his own thoughts and emotions .I thinks（think） the (加word)extroverted come(comes) from trover.The meaning of trover that it’s(is) finding(find) something easy(easily). The extroverted can be found from the face. So human add the ex to (去掉to)in front of trover .at last it be come(becomes) an extrovert.