题目内容：

    It seems every major city and town around the world hosts an annual marathon, with thousands of athletes running a gruelling 42.1 kilometres. While many runners' motivation is to beat their personal best and cross the finishing line without collapsing, they're also doing it for a good cause—to generate funds for charity. But like other major events, the marathon also generates a massive carbon footprint. Thousands travel —some by plane—to the location, and waste from food packaging and goody bags gets left behind by spectators and runners. This is becoming a big issue for cities—how to host a worthwhile event, encouraging people to exercise and help charities, while protecting the environment? Several cities have developed formal plans to reduce their environmental impact and promote sustainable （可持续的） ideas. One event in Wales, for example, introduced recycling for old running kit .

It's something that this year's London Marathon tried to tackle by reducing the number of drink stations on the running route, giving out water in paper cups and offering some drinks in eatable seaweed capsules. They also trialled new bottle belts made from recycled plastic so 700 runners could carry water bottles with them during their run. London Marathon event director Hugh Brasner told the BBC: “There are a lot of initiatives （倡议） we are using this year that we think will lead to some huge behavioural changes in the future.”

Meanwhile, some people still think running a marathon could be our best foot forward in helping the planet. Dr Andrea Collins from Cardiff University told the BBC: “Training for a marathon makes you more sustainable in day-to-day activities. I started walking or running to work every day and shunning public transport altogether. Being environmentally friendly while training sticks with you and becomes a way of life. ”

1.Why do many people enter for a marathon?

A.To achieve their own ambitions.

B.To generate a massive carbon footprint.

C.To improve themselves both physically and mentally.

D.To challenge their personal limitations and raise money for charities.

2.What did Hugh Brasner think of this year's London Marathon?

A.It may bring a large profit to London.

B.It saved a lot of water resources and power.

C.It may improve people's behaviour in the future.

D.It may make Londoners more friendly when running a marathon.

3.Which of the following can replace the underlined word “shunning” in the last paragraph?

A.Damaging. B.Avoiding.

C.Choosing. D.Changing.

4.What can we infer from the last paragraph?

A.Running a marathon can make more money.

B.Running a marathon can do great damage to the earth.

C.Running a marathon can change people's life completely.

D.Running a marathon can contribute to protecting the earth.