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1·The American College of radiology also recommends that all medical radiology units be professionally accredited, yet many are not.

美国辐射大学也建议所有的医疗辐射单位应该按职业进行授权，但是许多都没有。

2·The study, called the National Lung Screening Trial, was conducted by the American College of Radiology Imaging Network and the cancer institute.

这项研究叫国家肺癌筛查试验，由美国放射影像网络学院和美国癌症研究共同主持。