色谱法可分为气相色谱法(GC)和液相色谱法(LC)。GC根据固定相不同又可分为气固色谱法(GSC)和气液色谱法(GLC)，其中以GLC应用最广。按原理还可分为吸附色谱法,分配色谱法,离子交换色谱法,排阻色谱法和亲和色谱法。
气相色谱法(GC)和液相色谱法(LC)的分类是按照
A:固定相的聚集状态 B:流动相的聚集状态 C:固定相的几何形状 D:分离原理 E:流动相的化学性质
毒物对鱼类的半致死浓度（LC50）越大，表示毒物的毒性（）。
A:越大 B:越小 C:和LC50无关 D:有的大有的小
LC振荡电路和RC振荡电路比较（）。
A:RC输出功率小，频率较低，LC输出功率较大，频率也较高； B:RC输出功率大，频率较高，LC输出功率较小，频率较低； C:LC振荡电路的振荡频率大约在几赫到几十千赫的范围内，RC的振荡频率大约在几千赫到几百兆赫的范围内； D:LC振荡电路具有选频性，RC不具有选频性。
（）是变频器和LC调谐器放大器的共同点.
A:放大输入信号 B:自激振荡 C:产生的频率成分 D:用LC并联
LC震荡器与RC震荡器相比，其震荡频率表现为（）。
A:相等 B:LC震荡器高 C:LC震荡器低 D:RC震荡器高
LC表示（）。
A:气相 B:液相 C:液质 D:气质
Text 4
Under normal conditions the act of
communication requires the presence of at least two persons: one who sends and
one who receives the communication. In order to communicate thoughts and
feelings, there must be a conventional system of signs or symbols which mean the
same to the sender and the receiver.
The means of sending
communications are too numerous and varied for a systematic classification;
therefore, the analysis must begin with the means of receiving communication.
Reception of communication is achieved by our senses. Sight, hearing, and touch
play the most important roles. Smell and taste play very limited roles, for they
cannot receive intellectual expression from fully developed systems of signs and
symbols.
Examples of visual communication are gesture and
mimicry. Although both frequently accompany speech, there are systems that rely
solely on sight such as those used by deaf and dumb persons. Another means of
communicating visually is by signals of fire, smoke, flags, of flashing lights.
Feelings may be simply communicated by touch, such as by handshaking or
backslapping, although a highly developed system of hand stroking has enabled
blind, deaf, and dumb persons to communicate intelligently. Whistling to
someone, applauding in a theater, and other forms of communication by sound rely
upon the ear as a receiver. The most fully developed form of auditory
communication is, of course, the spoken language.
The means of
communication mentioned so far have two features in common: they last only a
short time, and the person involved must be relatively close to each other.
Therefore all are restricted in time and space. |
Which of the following senses plays the least important role in communication
A:Touch. B:Sight. C:Smell. D:Hearing.
荇信用证上关于汇票的条款规定：AVAILABLE BY YOUR DRAFT AT 30 DAYS SIGHT DRAWN ON APPLICANT，则此汇票应填写( )。
A:付款期限为AT 30 DAYS SICHT，付款人为开证申请人的名称 B:付款期限为AT 30 DAYS SIGHT，付款人为开证行的名称 C:付款期限为AT×××SIGHT，付款人为开证行的名称 D:付款期限为AT 30 DAYS SIGHT，付款人为“APPLICANT”
为在状态空间树中 (34) ，可以利用LC-检索(Least Cost Search)快速找到一个答案节点。在进行LC-检索时，为避免算法过分偏向于作纵深检查，应该 (35) 。
（35）处填（）。
A:使用精确的成本函数c(.)来作LC-检索 B:使用广度优先检索 C:使用深度优先检索 D:进行遍历
单项选择
