The wonders which medical workers have already brought about in the diagnosis and treatment of disease suggest that a time may come (56) the physician will be able to analyze most illnesses as (57) as they start, and cure (58) before damage results. How soon this "golden age of healing" arrives will (59) greatly on how close is the collaboration between research workers in medicine and (60) who work in the sciences on which medicine depends. The physician has (61) relied on the chemist for curative drags, and on the physicist for diagnostic instruments and healing rays. In the one field new materials and in the (62) new devices are (63) produced in increasing numbers, helping to (64) imminent new miracles of medicine.

The X-ray and the microscope (65) extended the vision of the medical observer (66) he can see (67) ten inches of living flesh or (68) a single tissue cell, yet similar but much more powerful tools (69) await development. Modem electrical devices (70) him to listen to faint murmurings of the life processes, or to measure feeble currents arising (71) heart and brain and nerve; yet electrical body measurements are (72) little understood. Now newly discovered atomic rays are being brought to (73) him destroy malignant invaders of the human system, and there is (74) reason to believe that even (75) curative rays await discovery.

63（）

电焊变压器的结构一般具有（）特点。

A、变压器绕组漏抗较大

B、变压器绕组漏抗较小

C、原绕组匝数可调

D、副绕组匝数可调