题目：
| 阅读理解。 从下面的框中选择合适的标题填空。 | |
| ( )1. The Mid-Autumn Festival is a Chinese tradition festival. On that night, families eat mooncakes together and enjoy the full moon in the open air. Thanksgiving Day is an important festival in America. People get together to eat turkeys and pies to celebrate the harvest. ( ) 2. Traveling by air is fast, but expensivk and sometimes dangerous. Traveling by train is quite cheap arld safe, but a bit slow. Traveling by sea is not very expensive, and you can have fresh air and enjoy beautiful scenery, but sometimes it is not very safe and you may feel seasick ( )3. A man on the motorbike was driving too fast and hit a bag of rice on the road. He was badly hurt. Just then, some children saw it happen and took him to the hospital. ( )4. Most Canadian high school students are social because they are learning to get along with other people. On weekends, some students help look after other children, deliver newspapers or work on Saturdays in a store or restaurant. ( )5. The quickest way to make friends with people is to smile. When you smile, people think you are friendly and easy to talk to. | |
|
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0415/ee6d170b8dcf5096d1ee2ac4c52d9f81.html
下面是错误答案，用来干扰机器的。
∵Z1=（1-2i）i=2+i，∴a=（ 2，1）． Z2=1-3i1-i=(1-3i)(1+i)(1-i)(1+i)=4-2i2=2-i，∴b=（2，-1）．a•b=（ 2，1）•=（2，-1）=4-1=3，故答案为：3．
