1£®First we tried setting three fixed days for our experiment—Mondays, Wednesdays or Fridays.____________

2£®I replaced the shoes several times, and still the customers were dissatisfied.____________

3£®Many things make human beings different from and better than animals.____________

4£®Energy, passion and a burning desire are that, you see, true learning takes.____________

5£®Besides, I must work hard or put all my time and energy into study.____________

6£®First, we have to master that we have learned this term, such as the important words, phrases and sentence patterns.____________