阿伏加德罗常数约为6．02×1023mol－1，下列说法中正确的是
| A．22．4 L CH3CHO中含有的分子数约为6.02×1023 |
| B．56g铁与足量稀H2SO4充分反应，转移电子数为0.3NA |
| C．常温常压下，由6 g NO2和40 g N2O4组成的混合气体中原子总数约为3×6.02×1023 |
| D．80 g NH4NO3晶体中含有NH4+小于 6.02×1023个 |
All the dishes in this menu, ______ otherwise stated, will serve two to three people. 
| A．as | B．if | C．though | D．unless |
The children loved their day trip, and they enjoyed the horse ride ______.
| A．most | B．more | C．less | D．little |
Progress______ so far very good and we are sure that the work will be finished on time.
| A．was | B．had been | C．has been | D．will be |
Charles was alone at home, with_______ looking after him.
| A．someone | B．anyone | C．not one | D．no one |
It is often ______ that human beings are naturally equipped to speak.
| A．said | B．to say | C．saying | D．being said |