题目

    In order to know a foreign language thoroughly, four things are necessary. Firstly, we must understand the language when we hear  61 spoken.Secondly, we must be able to speak it correctly with confidence and without hesitation.  62  ,we must be able to read the language,and fourthly, we must be able to write it. We must be able to make sentences that are grammatically correct.     There is no easy way to success  63  language learning.  64  good memory is of great help, but it is not enough only  65  (memorize) rules from a grammar book. It is not much use learning观察图并回答问题．心脏结构示意图：（1）体循环的起点是[ ] ，终点是[ ] ．（2）心脏中的瓣膜能起到防止血液倒流的作用，因此血液在该器官中是从 流向心室．（3）E血管中流动的血液是动脉血还是静脉血？ ．（4）肺循环将含氧较少的 变成含氧多的 ．