手术室内的有害化学物质污染包括下列哪些()
A．微量麻醉废气
B．甲醛
C．戊二醛
D．苯酚
E．激光器所释放的毒气
参考答案：A, B, C, D, E
△ABC的三边满足a2+b2+c2=ac+bc+ab，则△ABC是（ ）
A．等腰三角形
B．直角三角形
C．等边三角形
D．锐角三角形
Questions 6 to 10 are based on the following news.
A. Because the nuclear reactor is Pakistan’s property. B. Because Russia helped build the reactor in the 1960s. C. Because the uranium was provided by other nations. D. Because its neighbors are very sensitive about its nuclear program.
