下列方程式书写正确的
A．HCO3－在水溶液中的电离方程式：HCO3－＋H2O H3O＋＋CO32－ |
B．H2SO3的电离方程式：H2SO32H＋ ＋SO32－ |
| C．H2SO4的电离方程：H2SO42H＋＋SO42－ |
| D．CaCO3的电离方程式：CaCO3Ca2+＋CO32－ |
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 |