中医认为引起肛窦炎的病因,下列哪一项是正确的:
A.余毒未尽,蕴结不散
B.虫积骚扰,湿热内生
C.经络阻滞,淤血浊气凝聚
D.饮食不洁,久泻久痢
E.以上均不对
参考答案:B
A: What did you buy in the Computer World yesterday?
B: __51__I want to use it to record.
A: __52__
B: Well, I haven’t known yet._53___
A: Oh, no! You should read the instructions first.
B: __54__If you want to turn on the recorder, press the blue button”.
A: Look! It works. How do you save your video?
B: __55__
A: You’ve done that! Let’s try something to record.
一台小型发动机在3 V电压下工作,通过它的电源的电流是0.2 A,用此电动机提升重力为4 N的物体时,在30 s内可使该物体匀速提升3 m.若不计除电动机线圈发热以外的其他能量损失,求在提升重物的30 s内,电动机线圈所产生的热量.