如图装置进行实验，将液体A逐滴加入到固体B中，下列叙述正确的是 
| A．若A为浓硝酸，B为金属铜，C中盛有淀粉KI溶液，则C中溶液变蓝 |
| B．若A为浓盐酸，B为MnO2，C中盛石蕊试液，则C中溶液先变红后褪色 |
| C．若A为浓氨水，B为生石灰，C中盛A1C13溶液，则C中产生白色沉淀 |
| D．若A为浓硫酸，B为炭，C中盛有品红溶液，则C中溶液红色褪色 |
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 |