用坩埚钳夹住一小块刚用酸处理过的铝箔，在酒精灯上加热至熔化，发现熔化的铝并不滴落。下列关于上述实脸现象的解释不正确的是
| A．铝在空气中能很快形成氧化膜 | B．用酸处理时未能将氧化膜溶解 |
| C．氧化铝的熔点比铝高 | D．氧化铝薄膜包住了熔化的铝 |
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 |