Ⅰ.单句填空
1. Learning basic English before you travel will help you to understand these customs and avoid mistakes that could be ___________________(embarrass).
2. The term "herd behavior" comes from the behavior of animals in herds,___________________ (particular)when they are in dangerous situation.
3.You needn't install(安装）an expensive GPS system to keep track _____________________________your car.
4. By keeping the outside of the home __________________great shape, you will help to improve the look and feel of the area.
