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. ”

Like human beings, dogs may also catch a cold because of cold weather, wet conditions or can also get it from other sick dogs. If a dog has a running nose and watery eyes, or coughs, then it is quite probable that the dog has caught a cold. A dog can get over a cold after a few days.     10    The following are some of the things you can do if your dog gets a cold.

●Feed your dog with food that has proper nutrients.       11     This is because it can be harmful to his health. Instead, try to give him food, which is either recommended by the doctor or is healthy for your pet.

●Keep your dog warm. The best place for your dog in winter is inside your house. Don't keep him outside when it's cold and wet.       12     Keep him warm with the help of carpets at home. This will make him comfortable and help him to recover fast.

●    13     Water can be the best choice but you can also add broth (肉汤) in water. Check out the water you are feeding him if it is very cold and then just warm it a bit.

●Use steam treatment. Just fill your bathroom with steam    14    . Do it nearly two to three times a day and you’ll see your dog get better.