因式分x2+3x=______;x2-2xy+y2=______.
x2+3x=x(x+3);
x2-2xy+y2=(x-y) 2,
故答案为:x(x+3);(x-y) 2.
男,17岁,发热,双膝关节红肿痛,心尖区舒张期隆隆样杂音;Hb10g/dl。经治疗半年后复查杂音消失。可能诊断为()
A.风心病二尖瓣狭窄
B.左房粘液瘤
C.风湿性二尖瓣炎
D.贫血
E.Austin—F1int杂音
针刺不当易引起气胸的穴位是
A.天府B.中府C.尺泽D.侠白E.鱼际