单项选择题 Refer to the following Figure. If the relative cost of aluminum were to rise, then the production possibilities schedule would: Figure: Production Possibilities Schedule

单项选择题 The isometric self-regulation of the myocardium regulates the pumping function of the heart by changing A、initial length of myocardium B、arterial pressure C、ventricular end-diastolic volume D、myocardial contractility

判断题 多股芯线剥去绝缘物后,芯线可能松散,应进行捻紧,以便浸锡和焊接() A、正确 B、错误