The clinician then passes a smaller-caliber endoscope, 4.9 mm in diameter, through the nose, pharynx and throat.
The clinician then passes a smaller-caliber endoscope, 4.9 mm in diameter, through the nose, pharynx and throat.
临床医师这时就可以将更小口径的内窥镜（直径4.9毫米）通过鼻子、咽、喉。