在酯化反应和酯的水解反应中硫酸的作用分别是
All the dishes in this menu, ______ otherwise stated, will serve two to three people.
The children loved their day trip, and they enjoyed the horse ride ______.
Progress______ so far very good and we are sure that the work will be finished on time.
Charles was alone at home, with_______ looking after him.
It is often ______ that human beings are naturally equipped to speak.