Hi teachers, I want to know the differences between them. <br/>It confuses me every time I have to chose one <img class='emoticon' style='Width:19px;Height:19px;' data-delaysrc='https://uat-englishforward-forums-backend.s3.us-west-2.amazonaws.com/Emoticons/6.gif' src='https://uat-englishforward-forums-backend.s3.us-west-2.amazonaws.com/Emoticons/6.gif' alt='Emotion: sad'/><br/>Thanks!