避孕的原理为
A．抑制精子和卵子的产生
B．阻止精子和卵子的结合
C．抑制排卵
D．使子宫内环境不适合受精卵着床
E．提倡晚婚、晚育
参考答案：B,C,D
单词拼写。
1. He passed his examinations and now he has the ____ (学位) of Master.
2. He was s____ to three years in prison for stealing.
3. He gave the children some candies to ____ (奖赏) them for behaving well.
4. Can you show me the ____ (位置) of your hometown on the map?
5. He was made ____ (会长) of the cricket club.
软件工程方法中，表示软件处理流程的工具是 ______。
A．数据流程图
B．系统流程图
C．模块结构图
D．业务流程图
