Dragging a sleigh loaded with enough presents for the world’s children can be no easy skill. But, since ancient times, the Christmas Eve duty has been performed by a team of beloved reindeer.

Soon, however, Santa Claus may have to start looking around for a stronger type of animal, as newresearch shows the species is becoming increasingly puny. A 16-year survey on the arctic Norwegian islands, Svalbard, found the reindeer there have declined in weight by an alarming 12 percent.

The reduction in average body weight is being blamed on global warming. In the research presented lately at a meeting of the British Ecological Society in Liverpool, scientists have explained how upward temperatures are robbing female reindeer of nutrients during important periods of pregnancy.

Snow in Svalbard typically covers the ground for eight months of a year, which, combined with low temperatures, limits grass growth to June and July. But as summer temperatures increase by around 1. 5℃, grass has become more productive, allowing female reindeer to gain more weight by autumn and therefore to have more babies. However, winters have brought with them greater rainfall which freezes when it settles on the snow. Reindeer can often access the poor food sources beneath the snow by clearing it away with their antlers (鹿角) , but they cannot break through the hard ice. As a result, female reindeer are becoming starved, causing them to lose their babies or give birth to the much lighter young.

Despite the findings, reindeer appear to be suffering less from the effect of climate change than some other arctic species. Last week the scientists warned that a third of the world’s polar bears could disappear in the next 40 years.

   Many people would like to change various things in their life in order to be more eco-friendly. 【小题1】 They range from changing their jobs to their vehicles and even their homes. In what follows, I am going to talk about the most energy-efficient（节能的）small green homes. Keep on reading, as this article is very useful if you would like to change your home into a more eco-friendly one.

【小题2】 This happens because a green home will contain green devices（设备）which need alternative sources of energy such as solar power and wind power. They do not pollute the atmosphere as much as the regular sources of energy. 【小题3】 The process of installing them is kind of expensive but in the long term, it will save you a lot of money.

【小题4】 It will be made out of recyclable and renewable materials. For example, the furniture will be made out of bamboo instead of materials which take years to grow. This means that there is not a risk of them to be used up as in the case of certain types of wood or other materials.

A green house will be decorated by using non-toxic（无毒的）materials. 【小题5】 They contain harmful chemicals which can be dangerous, but the most energy-efficient small green homes do not have this problem.

I’m sorry to trouble you, but _________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Thank you!

Yours,

Li Ming