Travelling is very interesting. Many people love travelling.There are many ways to travel：by plane，by train，by ship or by car. Everyone has their favourite way.

    Greg：My favourite way of travelling is by car. I can bring my pet dog along. I can travel three hundred miles or only fifty miles a day. I can stop at a good restaurant to enjoy a good meal or at a hotel to spend the night.

    Eliza：I love travelling by train best! It's very exciting. I travelled most of Europe in 5 months by train. It's the best way to talk with the local people and make new friends on the way. Trains make the long trip enjoyable. The train ride to me is just like a big moving party.

    I also like travelling by ship. It is a very great way to spend a holiday. I can go to parties and watch movies on the ship，and enjoy the blue sky and water.

    Danny：Travelling by plane is my favourite. It's the fastest way. I can quickly get to another country. Planes have very comfortable seats. I can have something to drink and eat. I can also read some free magazines and newspapers.

“中国好声音”比赛现场，吉他手弹奏电吉他时不断用手指去控制琴弦长度，这样做的目的是为了改变声音的____ ；琴声是通过____ 传播到现场观众耳中的．观众在听音乐时都要把手机关机或把铃声调成振动，目的是为了在____ 减弱噪声．

为鼓励居民节约用水，某市规定：每月用水量在20吨以内的，每吨水价1.8元；超过20吨的部分，每吨水价2.5元．小青家上个月缴水费43.5元．她家上个月用水____吨？

为缓解城市交通压力，近几年成都大力发展有轨交通，几条地铁线路已经开通运行，同时又在积极投建有轨电车，以取代部分用柴油机作动力的公交车。于电车和柴油车，下列说法不正确的是（ ）