Forests provide ________ shelter ________ food for animals and insects．

1. A.
   both; and
2. B.
   many; and
3. C.
   both; or
4. D.
   many; or

World Wildlife Fund (WWF)'s goal is to save the world's environment. The organization was set up ___21__September 11，1961. In the beginning, WWF worked __22__ the world's wildlife. Now, it works to save Earth__23___ its environment.

WWF has many tasks. One is to stop air pollution. Pollution from industry(工业)  and cars is _24_ to our environment. Each year, more and more trees are cut down __25__WWF tries to protect Earth's forests．Also people use more land, more and more animals are __26__ their homes and many die. WWF can buy important areas to __27__ the land from disappearing because of human development.

WWF has completed many projects. In China, WWF works to save pandas from  extinction（灭绝）． ___28__South America，it works to save the Amazon Rainforest.  Volunteers and donations help WWF complete its work. WWF's work is __29__to our environment, and is also important for people to help them __30__ time and money.