从A、B、C、D中选出适当的字母或组合，使所给单词完整与正确：

________ ght

[　　]

根据首字母，用词的适当形式填空

The pleasant smell r________ for long.

根据首字母，用词的适当形式填空

It's important to r________ paper to save the trees.

根据首字母，用词的适当形式填空

Polar bears are very a________ animals.

根据首字母，用词的适当形式填空

The white wall in the hospital makes me very t________.

根据首字母，用词的适当形式填空

The design of the restaurant is very s________ according to the influence of different colours to people.

根据首字母，用词的适当形式填空

Often we just walk around the town center, s________ as many of our friends we can.

根据首字母，用词的适当形式填空

G________ he can understand what his mother did for him.

根据首字母，用词的适当形式填空

What's the p________ of the world？ It's aver 6 billion.

根据首字母，用词的适当形式填空

I've r________ out of the petrol in the tank, it's empty.