Gerneally speaking, it is difficult to breathe at a high       of Tibet (西藏).

 Mary was given a huge pay rise as a       for her great efforts in improving sales.

After the earthquake, the government turned a school into a      for the victims of the earthquake.

This extra effort makes a lasting _________, the kind that often results in some fortune with extra business.

Speaking of Utopia, a popular explanation is that it’s an ideal world, or a perfect final _________.

Urban (城市) crowdedness would be greatly relieved if only the_______ charged on public transport were more reasonable.

As the years passed, many _________—birthdays, awards, graduations—were marked with Dad’s flowers.

Ancient Greeks were responsible for many of the _______ in science and other fields．

Quite a few people like traveling, for it can increase their knowledge and broaden their _____．

The       of surfing the Internet is how you can tell whether the information is true or not.

He often asks his neighbour to look after his pet during his _______.

We must keep on learning if we want to keep up with the     of the changing times.

 The American girl has a good          of Chinese and can express herself freely in the language.

---Why not advise Tom to join us? ---He is as ____ as his brother, who never listens to others’ opinions.

I prefer to eat in that restaurant, because the ____ of service there has improved a lot.

The man has gained an evil reputation. That’s to say he has a bad _____.

Perhaps the beautiful beach is the island’s main ______. It is always full of tourists.

Our English teacher，Billy，never criticizes us，but uses        to make us work hard.

 ---- Why don’t you try to do exercise to lose weight? ---- I have tried everything but it has made no _____________.

Nowadays, few people form the habit of keeping the habit of candles in the house in case of  power      .