下图的实验装置用来分离CO2和CO气体并干燥。图中a为止水夹，b为分液漏斗的活塞，通过Y型管和止水夹分别接c、d两球胆，现装置内的空气已排尽。为使实验成功，甲、乙、丙分别盛放的溶液是
| A．NaHCO3饱和溶液 12 mol·L－1盐酸 18.4 mol·L－1H2SO4 |
| B．Na2CO3饱和溶液 2 mol·L－1H2SO4 NaOH饱和溶液 |
| C．NaOH饱和溶液 2 mol·L－1H2SO4 18.4 mol·L－1H2SO4 |
| D．18.4 mol·L－1H2SO4 NaOH饱和溶液 18.4 mol·L－1H2SO4 |
They use computers to keep the traffic _______ smoothly.
| A．being run | B．run | C．to run | D．running |
If you leave the club, you will not be_____back in .
| A．received | B．admitted | C．turned | D．moved |
What I need is_____ book that contains ______ABC of oil painting.
| A．a; 不填 | B．the; 不填 | C．the; an | D．a ; the |
Jenny nearly missed the flight______ doing too much shopping.
| A．as a result of | B．on top of | C．in front of | D．in need of |
The CDs are on sale! Buy one and you get ______ completely free.
| A．other | B．others | C．one | D．ones ks |