“几处早莺争暖树，谁家新燕啄春泥。”早莺叽叽喳喳争抢洒满阳光的枝头，燕子飞进飞出忙着啄泥搭窝。白居易的诗句以对早莺新燕的喜爱衬托春天的生机和活力，引发了作者热爱春天、热爱生命的美好情感。对此理解正确的是（    ）

B

Climbing Mount Everest, the world’s highest mountain, has now become more difficult. The government of Nepal asks climbers to come down the mountain with at least 18 pounds of garbage. That’s the average amount of garbage a climber leaves behind on Mount Everest.

Climbers would leave garbage along the way. This helps climbers keep their bags light, so they would have energy to reach the summit. The garbage problem in Mount Everest is not new. In 2013, climbers carried down a total of four tons of garbage.

The new rule came into effect in April of 2014. To make sure it is followed, climbers will have to hand in some money to the officials before they climb the mountain. When they climb back down the mountain, the officials will check them to make sure they bring down the 18 pounds of garbage. If they do, their money will be given back to them. If not, climbers won’t get their money back. Also, the officials won’t let these people climb the mountain again.

人体进行消化和吸收主要部位是