阅读短文，根据短文内容补全所给的五个残缺的句子。每空只能填一词。

There is a big zoo in our city. There are lots of animals in it. The tiger is from India. Its favourite food is meal. The giraffe is very tall. It comes from Africa. There are three pandas in the zoo. They come from China . They like eating bamboo very much. Each panda eats fifteen likos of bamboo every day . We like animals very much. They are our friends.

小题1:There are a lot of ________________ in the zoo.

小题2:The tiger is from _______________.

小题3:The giraffe is very ______________.

小题4:The three pandas like eating ________________ very much.

小题5:The three pandas eat ______________ kilos of bamboo a day.

消息缓冲通信技术是一种高级通信机制，由Hansen首先提出。请回答下列问题：

给出消息缓冲机制(有限缓冲)的基本工作原理；