Scholars offer three related but different opinions about different opinions about the__________ (mystery)origin and significance of these paintings.

Time is dangerous.If you don’t control it，it will control you.If you don't make it work for you，it will work against you.You must become the master of time，not the servant.

Study hard and play hard is an old proverb，but it still makes sense.You have plenty of time for classes，study and play if you use your time properly.It is not how much time you allocate for study that counts but how much you learn when you do study.

The more time you waste，the easier it is to continue wasting time.Soon, doing nothing becomes a habit you can’t break.It becomes a drug.When this happens，you lose your feeling of accomplishment.

最近的研究表明，白日做梦是日常生活的一部分。

你需要更多的练习，这是很明显的。

要不是她的妈妈，她是读不完大学的。

今年热得很不寻常。

你一旦开始，就必须继续下去。

He is__________ (habit)late for school;he is never on time.

It would be completely__________ (responsible)to use drugs on people that had not been tested on animals.

We took a contrary view, but we have to implement and(force]the law passed by Congress.

In addition to intelligence，we should develop__________ (persist)in children.