正弦交流电的周期用（）来表示。_电缆线务员(技师)_全学科试题题库

当前学科：电缆线务员(技师)

题目：单选
正弦交流电的周期用（）来表示。
答案： <查看本题扣1积分>

查看答案

答案不对？请尝试站内搜索

推荐知识点:

下列项目中属于流动资产的是( )。 A．交易性金融资产 B．预付账款 C．预收账款 D．待摊费用

在车辆贷款中，可用来作为质押物的为：（）

简述新生儿窒息的初步复苏步骤。

柜员短期离岗，需认真办理交接，交接双方及监交人员签章确认，交接主要流程包括()。

导轴承间隙应由有经验的两人测量，允许误差在（）mm之内。

下列与普鲁卡因的理化性质相符的是

回答题: Exercise Being Good or BadCan exercise be a bad thing? Sudden death during or soon after strenuous exertion on the squash court or on the army training grounds, is not unheard of. 51 trained marathon runners are not immune to fatal heart attacks. But no one knows just 52 common these sudden deaths linked to exercise are. The registration andinvestigation of such 53 is very patchy; only a national survey could determine the true 54 of sudden deaths in sports. But the climate of medical opinion is shifting in 55 of exercise, for the person recovering from a heart attack as 56 as the average lazy individual. Training can help the victim of a heart attack bylowering the 57 of oxygen the heart needs at any given level of work 58 the patient can do more before reaching the point where chest pains indicate a heart starved of oxygen. The question is, should middle-aged people, 59 .particular, be screened for signs of heart disease before 60 vigorous exercise?Most cases of sudden death in sport are caused by lethal arrhythmias in the beating of the heart, often in people 61 undiagnosed coronary heart disease. In North America 62 over 35 is advised to have a physical check-up and even an exercise electrocardiogram. The British, on the whole, think all this testing isunnecessary. Not many people die from exercise, 63 , and ECGs ( 心电图 ) are notoriously inaccurate. However, two medical cardiologists at the Victoria Infirmary in Glasgow, advocate screening by exercise ECG for people over 40, or younger people 64 at risk of developing coronary heart disease. Individuals showing a particular abnormality in their ECGs 65 , they say, a 10 to 20 times greater risk of subsequently developing signs of coronary heart disease, or of sudden death.第51题应选：

患者，女，55岁。三月前无明显诱因出现右上肢疼痛，以后症状逐渐加重，近2天，扫地、扭毛巾等细小的生活动作均感困难。体查：桡骨头附近有一局限性、极敏锐的压痛点本病的特殊检查是（）。

经（）以上的业主提议，业主委员会应当组织召开业主大会临时会议。

二度Ⅰ型房室传导阻滞，阻滞部位多位于（）；二度Ⅱ型房室传导阻滞，阻滞多位于（）。