最常见的牙周病是（） A.急性牙周炎 B.慢性牙周炎 C.牙周变性 D.牙周萎缩 E

不适宜用离子交换树脂分离的成分是( )

A．生物碱

B．生物碱盐

C．有机酸

D．氨基酸

E．强心苷

氢气是重要而洁净的能源，要利用氢气作能源，必须安全有效地储存氢气。有报道称某种合金材料有较大的储氢容量，其晶体结构的最小单元如下图所示。则这种合金的化学式为

A．LaNi₆

B．LaNi₃

C．LaNi₄

D．LaNi₅

从触电（）分钟开始救治者，10％有良好效果.

A.2

B.4

C.6

甲到本村乙家买柴油时，因屋内光线昏暗，甲欲点燃打火机看油量。乙担心引起火灾，上前阻止。但甲坚持说柴油见火不会燃烧，仍然点燃了打火机，结果引起油桶燃烧，造成火灾，导致甲、乙及一旁观看的丙被火烧伤，乙、丙经抢救无效死亡。后经检测，乙储存的柴油闪点不符合标准。甲的行为构成何罪（）

A.危险物品肇事罪

B.失火罪

C.放火罪

D.重大责任事故罪

In (85) software, one question of near-universal interest is how rapidly Windows NT, which began shipping last summer, will be (86) in the marketplace and for what uses. For the most part, observers are (87) about the operating system’s long term prospects, but expect it to remain on (88) rather than desktops during 1994, saying that it won’t become a mainstream product until (89) PCs typically have 16 to 24 MB of RAM, which is unlikely to happen next year.

A．applications

B．accepted

C．clients

D．enthusiastic

E．servers

F．desktop

G．systems

H．replaced