1 . As there is less and less coal and oil, scientists are exploring new ways of making use of ______ energy, such as sunlight, wind and water for power and fuel.

A．primary

B．alternative

C．instant

D．unique

2 . 请用方框中单词或短语完成句子，并将答案书写在相应位置。

focus on 　　　explore 　　　struggle　　　 work out 　　　unique

1. The mental strength that Jordan showed made him ___________.
2. Soon she made friends and began to ___________ the city with them.
3. Come and ___________ at a gym. Sweat your way to good health!
4. Spending too much time online makes it difficult to ___________ other things in life.
5. When I started studying German, it was a ___________. The words felt strange on my tongue.