Translation. 英汉互译。

1. last week                                         6. 穿裤子                                 

2. have breakfast                                  7. 公共汽车司机                       

3. a police officer                                 8. 三百米                                    

4. each other                                        9. 今天上午                              

5. work hard                                        10. 足球队                                

简述冻精的原理及牛冻精的制作。