燃料的高位发热量与低位发热量的区别在于水的汽化潜热。
参考答案:对
Audiences and critics were _____ by its originality, vitality, and excitement of the Beijing Olympic opening ceremony. [ ]
A. happened
B. reflected
C. occurred
D. struck
下咽癌易有颈淋巴结转移,故用根治性放疗方法时,其照射野()
A.只需照射原发病灶
B.原发病灶+邻近淋巴结引流区
C.原发病灶+上、中、下颈淋巴引流区
D.上到口咽,下至颈段食管入口水平吐颈淋巴引流区
E.上至口咽,下至颈段食管入口水平+全颈及锁骨上区淋巴引流区