【单选题】数据通信中的信道传输速率单位是bits/秒,被称为 ( ) ,而每秒钟电位变化的次数被称为 ( ) .
【简答题】实验室中有一瓶浓度均为0.1 mol·L -1 的Na 2 SO 4 和H 2 SO 4 的混合溶液,量取100 mL置于锥形瓶中,向其中逐滴加入0.2 mol·L -1 的Ba(OH) 2 溶液并不断搅拌,使反应充分进行(假设混合后溶液的体积为两者之和)。 (1)当加入50 mL Ba(OH) 2 溶液时,所得溶液中溶质为________,其物质的量浓度为____mol·L -1 。 (2)当溶...
【单选题】一般而言,与疫情有关的对应产品是不能进口的。( )
【简答题】Centuries ago, man discovered that removing moisture from food helps to store it, and that the easiest way to do this is to expose the food to sun and wind. All foods including water — cabbage and oth...
【单选题】The longer an oil fire is permitted to burn, the _____.
A.
harder it is to extinguish
B.
easier it is to extinguish
C.
less chance there is of re-ignition
D.
easier it is to control
【单选题】Which of the following statements is INCORRECT according to the conversation?
A.
It is easier to master mother tongue than any other language.
B.
Training class is helpful.
C.
Foreign language can make us work better.
D.
Six hours' practice is necessary to learn a foreign language fast.
【判断题】综合版凸印技法可以选择厚一些的水彩纸做底板进行制版。
【判断题】汗水的味道中蕴含着基因密码,而人类的鼻子能迅速识别这一密码。
【单选题】The author wanted to be a writer because______.
A.
he liked to take risks
B.
he found it easier to make a living by writing
C.
he was interested in writing
D.
he could not study medicine well
【单选题】《灵枢 • 天年》篇言: “人生十岁,五脏始定,血气已通,其气在下,故好( )”