计算：（﹣8）+5=____ 

河蚌属于哪一类动物？

     Bamboo (竹子) is one of nature's (自然) most surprising plants. Many people call this plant a tree, but it is a kind of grass.
Like other kinds of grass, a bamboo plant may be cut very low to the ground, but it will grow back very quickly. A Japanese scientist reported one bamboo plant which grew 1. 5 metres(4 feet) in 24 hours! Bamboo grows almost everywhere in the world except Europe. There are more than 1, 000 kinds of bamboo.
     Not all bamboo looks the same. Some bamboo plants are very thin. They may only grow to be a few centimetres wide while others may grow to more than 30 centimetres (1 foot) across. This plant also comes in different colours, from yellow to black to green.
Bamboo has been used to make many things such as hats and kitchen tools( 厨房用具). Because it is strong, bamboo is also used to build buildings.
      Many Asian countries have used bamboo for hundreds of years. They often use bamboo for buildings and supporting (支撑) new buildings and bridges while they are being built.
      In Africa, poor farmers are taught how to find water using bamboo. These African countries need cheap way to find water because they have no money, and their fields often die from no rain and no water. Bamboo pipes( 管子) help poor farmers bring water to their thirsty fields without spending a lot of money.