某县、乡镇两级人民代表大会同步进步的换届选举中，不少县区组织各选区人大代表候选人与选民见面，让每位候选人“登台亮相”，发表“竞选演说”，与选民进行近距离交流。这一做法（    ）

①表明我国间接选举和等额选举相结合

②有助于选民了解候选人，提高选举积极性

③反映了我国社会主义民主政治的进步

④有利于充分考虑当选者结构的合理性

移栽树苗时，常剪去部分枝叶，主要目的是（　　）

2010年1月17日，永州市区的空气污染指数为58，首要污染物为：可吸入颗粒物．根据以上信息，判断永州市区当天的空气质量级别和空气质量状况分别是（   ）

    Dear Adam,

    I'm on vacation in Central America and having a great time. I'm in Guatemala. It's a small country but there is so much to see and do! There are volcanoes (火山), mountains, rainforests, beaches and Mayan temples (玛雅寺庙) in the country.

    The Mayan people have a long and interesting history. They built many temples. Last Friday I visited a Mayan temple at a place called Tikal. The temple has a history of about 1,300 years. It is a wonderful place to visit.

    I am staying at Lake Atitlan now. Some people say it is the most beautiful lake in the world. It is a very big lake and there are mountains and volcanoes around it. You can walk around the lake and even climb to the top of a volcano.

    The volcanoes at Lake Atitlan are not active volcanoes (活火山), but tomorrow I am going to see an active volcano called Pacaya. Active volcanoes can be dangerous because they still erupt (爆发) sometimes. I want to climb Pacaya. It erupted in 2010. I hope it won't erupt when I' m there!

      I'll send (发送,) you another e-mail soon.

                                                      All the best,

                                                       Kate