据统计，全球每年因老鼠损失贮粮3500多万吨，因鼠害减产5000万吨，足供3亿人吃1年。此外，老鼠还是各种鼠源性疾病的传染源。全球90%的鼠种，携带着200多种病原体，能使人致病的病原体主要有57种。据此完成：

鼠害对我国农业生产已造成很大威胁，我们应加强灭鼠保粮工作，下列措施中最科学的是(   )

    I am ____  (计划)to travel from London to Amsterdam. There are four ways to travel.

    A ____ (旅程) by train is more relaxing ____ by coach, but a lot more expensive.

    You can go by car and by ship across the North Sea. This is the ____comfortable way to travel. ____(停车) in Amsterdam is very expensive, so stay outside the city centre and travel in by bus or by train.

    The____(three) choice is by coach. This is usually the ____(cheap), but in summer the coaches sometimes get ____(拥挤的)! And it ____(花费)you about twelve hours to get there.

    Finally, you can fly. It is the fastest, but you may have to wait for ____(小时 )at the airport because of bad weather.