有一电池当外电路电阻为2.9 Ω时测得的电流强度为0.5 A;当外电路电阻为1.4 Ω时测得的路端电压为1.4 V,求电源的电动势和内电阻.
— Do you know the Capital Museum?
— Next Friday.
A.when will they visit
B.when they will visit
C.when did they visit
D.when they visited
女性,40岁,经常出现牙龈出血,并时有鼻出血和球结膜出血,每次月经量较多,偶有外伤时伤口愈合缓慢,检查其口腔发现牙龈肿胀、出血。
可疑其患有的疾病是()。
A.癞皮病
B.周围神经炎
C.脚气病
D.维生素C缺乏病
E.毛囊角化症