常用的连接性副词主要有however， therefore， nevertheless， as a result， instead， thus， in contrast， similarly， for example， at the same time， on the other hand， consequently， in addition， furthermore等。1. The zoos _____________________________________; ___________， they keep city people in closer contact with the more natural world.
动物园，，它们还使城市居民有机会接触到自然状态下的动物世界。2. Cloning could be used to increase the population of _________________________ of animals and thus save them from total ______________.
克隆技术可能被用来增加的数量，从而避免它们的。3. Some people are using bicycles for transportation; ___________， others are ______________ or taking ________________ to get to their destinations.
有些人使用单车作为交通工具，有些人使用汽车或搭乘去他们的目的地。4. Intelligent machines such as robots can replace humans to do some dangerous tasks; ___________， they release housewives from ____________________________.
智能机器，如机器人，能代替人从事许多危险的工作，，它们也使家庭主妇从中解脱出来。5. The company produces poisonous gases day and night; _________________， ________________________________among residents nearby _________________.
那家公司整天制造出有毒气体，，附近居民。
本期题目：
请将题目中的空格填上。
答案:
1.conserve many forms of wildlife， furthermore 2.endangered species， extinction 3.moreover， joining carpools， public vehicles 4.in addition， daily household chores 5.consequently， the incidence of cancer， skyrockets