口腔颔面部恶性肿瘤以哪种肿瘤最为常见()
A.腺源性上皮癌
B.鳞状上皮细胞癌
C.未分化癌
D.各类肉瘤
E.恶性淋巴瘤
参考答案:B
—Would you like to go to the shopping mall with me tonight?
—I’d like to, but I have to attend a lecture _______ in the school library.
A.given
B.being given
C.having been given
D.to be given
当发电机输出电压高于蓄电池电压,一般发电机的转速达到1000r/min左右时,励磁电流便由发电机自身供给,这种励磁方式称为()。