短文填词 （共10小题，每小题1分，满分10分）

Books are our friends. They introduce us many different kinds of knowledge.

They lead us down the road to __小题1:___(成功). Books are our teachers. They ___小题2:___ us truth, science, literature, and philosophy of life; ____小题3:__ (此外)，they increase our knowledge, enlarge our experience, strengthen  our character and do many o__小题4:___ things which we can __小题5:___  do without them. We have to learn as long as we live. Butour life is ___小题6:___ (有限的), and the knowledge is boundless. There aremany things __小题7:___ are very necessary to learn and there are also manywhich should be ___小题8:__ (回避). Books tell us what is good and what is not. And only books can tell the good __小题9:___ the bad. Therefore, to read more books is the b_小题10:___ policy for us young students.

隐孢子虫的感染阶段是__________