油枕的作用是:()油量;()的使用寿命,油枕的容积一般为变压器总油量的十分之一。
参考答案:调节;延长油
We _____ have proved great adventurers, but we have done the greatest march ever made in the past ten years.
A. needn't
B. may not
C. shouldn't
D. mustn't
患儿,女,7岁,左下颌乳侧切牙松动Ⅲ°,侧切牙已于舌侧萌出牙冠的1/4,乳牙拔除时应选择的麻药及麻醉方式()
A.2%普鲁卡因行唇、舌侧局部浸润麻醉
B.2%利多卡因行唇、舌侧局部浸润麻醉
C.2%含肾上腺素普鲁卡因行左侧下牙槽神经、舌神经、颊神经阻滞麻醉
D.2%含肾上腺素利多卡因行左侧下牙槽神经、舌神经、颊神经阻滞麻醉
E.2%地卡因行局部表面麻醉