B
Last week, scientists said they discovered a new birdlike dinosaur. With feathers, a beak (鸟嘴) and long legs, it looked pretty funny. This kind of dinosaur was 3 meters (10 feet) long, and it was higher than most humans. It also had sharp claws (爪子).
Fossil hunters dug out the bones of this species in a rocky place of southwest North Dakota. The scientists nicknamed this dinosaur the "Chicken from Hell". They also gave it a more formal name: Anzu Wyliei. Anzu was a mythical (神秘的) fire-breathing bird. Wylie is the dinosaur-loving grandson of a man who supports the Carnegie Museum of Natural History in Pittsburgh, Pa. Scientists at that museum were part of the team that told the new dinosaur in a paper published on March 19 in the journal PLOS ONE. "The Anzu dinosaur is based on a surprisingly nice specimen(样品), and past digs turned up this animal," a scientist told Science News for Students.
实验装置 | 实验步骤 |
①连接装置并检查气密性 ②向甲、乙玻璃管内加适量的水,在燃烧匙里放足量红磷并塞紧塞子,调节两支玻璃管内液面相平,并将甲管上方的空气五等分。 ③加热铜丝,待红磷燃烧后,熄灭酒精灯。 ④待温度恢复至室温,水不再进入甲玻璃管时,调节乙玻璃管的高低至两边液面再次相平。 |
材料一 马尔代夫是印度洋上的群岛国家,2009年10月17日,马尔代夫总统召开全球首个海底内阁会议,参会人穿上潜水衣、戴上潜水镜和潜水装置,潜入约6米深的海底进行会议。由于人们焚烧化石矿物或砍伐森林并将其焚烧时产生二氧化碳等多种温室气体,加剧了“温室效应”,导致全球气候变暖。全球变暖的后果,会使冰川融化,海平面上升,引起各地降水和干湿状况的变化等,既危害自然生态系统的平衡,更威胁人类的食物供应和居住环境。
材料二 我国约90%的煤炭资源分布在秦岭以北地区,华北地区耕地约占全国耕地面积的40%,水资源约占全国的6%.
在平面直角坐标系中,抛物线y=x2+(k﹣1)x﹣k与直线y=kx+1交于A,B两点,点A在点B的左侧.
①小明通过网络倡导同学参与节假日志愿者服务活动
②小欣在朋友圈转发了新华公益网站上的一则募捐信息
③小红通过网络响应中学生诚信考试的倡议
④小磊通过网络转发一些反电信诈骗的方法