滴定时，加入半滴溶液的方法是（）A.用滴定管将管尖紧贴容器内壁，用锥形瓶内壁将溶液沾落B.轻轻转动旋塞，使溶液悬挂在出口管嘴上，形成半滴溶液C.用洗瓶吹洗锥形瓶内壁D. 以上都是

A
B
C
D

滴定分析实验中使用的准确量器有（）A.烧杯；B.锥形瓶；C.移液管或吸量管；D.量筒

A
B
C
D

用Na2CO3标定盐酸时，锥形瓶在用蒸馏水洗净后没有晾干就直接装入准确称量的Na2CO3，这会使最后滴定分析的结果（）。

A. 无影响
B. 偏低
C. 偏高
D. 以上结论都不对

关于滴定操作，下列说法中正确的是（）A、滴定过程中应时刻注意观察滴定管中液面的读数；B、滴定中一般用左手控制滴定管活塞，右手握住并利用腕力旋转锥形瓶；C、滴定速度一般应先慢后快；D、向滴定管中加入操作溶液时一般采用玻璃棒引流的方法来防止溶液溢出。

A
B
C
D

下列不能用于清洗比色皿的试剂是（）A. 蒸馏水； B. 盐酸：乙醇为1：2的混合液；C. 强氧化性洗涤液 D.乙醇

A
B
C
D

下列仪器中不需要润洗的仪器是（）A. 滴定管；B.锥形瓶；C.移液管；D.吸量管

A
B
C
D

标定过程中用于接装基准物的锥形瓶是否干燥下列说法正确的是（ ）A.内壁必须干燥 B.内壁不必干燥 C.外壁必须干燥 D.内壁挂珠即可

A
B
C
D

使用移液管移取溶液时应该使用哪根手指操作移液管上口（）A.食指 B.中指 C.拇指 D.小指

A
B
C
D

Complete the company profile of a French energy company, by choosing the correct word A-D below to fill each gap.EDF is one of the largest electricity companies in the world with a (0) turnover of 59 billion Euros in 2006. Its 1 ______ are in Paris, and it is the dominant player in France, with over 80% of the market. Its largest2_____, 100% owned by EDF is EDF-Energy which supplies over five million customers in the UK.The company has three main 3 _______ electricity production, of which 70% comes from nuclear power 4______; distribution; and retail or supply. The first two are very technical activities. The third, retail, is more customer focused. Nowadays, most customer contact is handled by 5_____ centres, where operators manage customer enquiries online or over the telephone. Electricity is an unusual product. It cannot be stored in a 6_____ like other goods. What you produce has to be consumed immediately. So, supply and demand have to be balanced exactly on a day by day, or hour by hour basis.0 A sales B turnover C income D figure