问题 选择题

腐烂的水果往往会散发出酒的气味,引起这种现象的生物是(  )

A.霉菌

B.细菌

C.蘑菇

D.酵母菌

答案

酒是一种发酵食品,它是由一种叫酵母菌的真菌分解糖类产生的.酵母菌是一种分布极其广泛的菌类,在广袤的大自然原野中,尤其在一些含糖分较高的水果中,这种酵母菌更容易繁衍滋长.当成熟的野果坠落下来后,由于受到果皮上或空气中酵母菌的作用,水果内的葡萄糖被分解产生酒精,就是我们的日常生活中,在腐烂的水果摊附近,都能常常嗅到由于水果腐烂而散发出来的阵阵酒味儿的原因.

故选:D

阅读理解

阅读理解。

     A couple (夫妇) have travelled around the world in 297 days-without taking any planes. Tom Fewins and

Lara Lockwood used 78 buses, 61 trains, 34 cars, 18 boats, six bicycles, and even one elephant. They wanted

to prove that tourists can still be well travelled without damaging the environment. They aimed to product less

than 3,000 kg of carbon dioxide (二氧化碳), compared with six times that amount if they had gone by plane.

    They spent ten months travelling 44,609 miles through 18 countries on land and sea. The couple's world

tour began in June 2008 with a two-hour bus journey to London from their home in Oxfordshire. They took

the train, Eurostar, to Brussels and then caught a bus and train to Hamburg before going to Copenhagen.

     The couple even rode on an elephant for l 5 miles through the Chinese part of the Mekong River (湄公河).

The couple hoped to write a book based on their journey to teach other travelers how to travel without

damaging the environment.

1. How long did it take the couple finish their journey?

A. About 78 days

B. About 34 weeks

C. About 10 months

D. About a year

2. Where did the couple begin their tour?

A. London

B. Oxfordshire

C. Brussels

D. Copenhagen

3. How many ways of transportation did the couple use to travel around the world according to the passage?

A. Four

B. Five

C. Six

D. Seven

4. Why did the couple travel like this?.

A. They liked to travel in this way.

B. They aimed to product 3,000 kg of carbon dioxide.

C. They wanted to prove that tourists can still be well travelled only by bike.

D. They hoped to write a book and taught the travelers to protect the environment.

单项选择题