June 5 th is World Environment Day. This makes us pay more attention to our environment. When Wang Boxuan, a Beijing high schoolboy, uses up his exercise-books, he does not throw them away. Each one is kept at his school, together with hundreds of exercise-books that are given by other students. Then they are sold to a paper making factory in Beijing. The paper is recycled and used again by students and teachers in the school. At the same time, the money that is made from the sales goes to poor areas. People there use the money to plant more trees and grass. Sandstorms( 沙尘暴 ) from this place often do harm to Beijing in spring. Wang's school is one of the schools in the capital that take part in the "Green Promise" environmental protection activity. So far, nearly 80% of the students have joined in the activity and collected more than 87 tons of waste paper. ( ) 65. All the students have joined in the activity, collecting over 87 tons of waste paper. A. True B. False