Proctitis is common in patients undergoing pelvic radiation therapy.直肠炎常见于骨盆放射治疗的病人.This new plane is undergoing safety tests.这架新型飞机正在接受安全试验。New recruits have been undergoing training in recent weeks.最近几周，新兵正在接受训练。In 21 ...
雪白的山峰同蔚蓝的天空交相辉映.This white peak contrasts finely with the blue sky.蔚蓝的天空晴朗无云.The sky is quite blue and cloudless.蔚蓝的天空不一定担保天气持续晴朗.Blue skies are not a guarantee of continuing fine weather....