下列属于传染病的疾病是（ ） A、高血压 B、心脏病 C、蛔虫病 D、骨折
实验室用高锰酸钾制取氧气分为下列几个步骤：①点燃酒精灯，加热试管；②检验装置的气密性；③将高锰酸钾装入试管，试管口塞入一团棉花，用带
It was in the past two years that Aaron Segura was always sinking at West Mesa High School in Albuquerque, New Mexico. The 16yearold student was __1__ in golf, but his __2__ was another matter.
（上海卷理16文16）如图，在棱长为2的正方体 ABCD-A1B1C1D1中，E是BC1的中点，求直线DE与平面 ABCD所成角的大小（结果用反三角函数表示）
阅读下面的文言文，完成文后各题。 贾耽，字敦诗，沧州南皮人。天宝中，举明经，补临清尉。河东节度使王思礼署为度支判官。累进汾州刺史，治凡
双曲线的离心率是2，则的最小值为 A. B. C.2 D.1
On December 10,2013,many world’s top leaders went to Johannesburg _____Nelson Mandela, who had passed away. A. in honor of B. in favor of C. in search of
