27. Nearly four hundred supermarkets in Beijing are preparing to dim their lights ________ the "Earth Hour 2010" on Saturday night.
The medicine is supposed to cure this disease, but I’m not sure it.
----No one is so ____ about his joy as Doctor Li. ----You are right. He devotes all his time and energies to his cause.
Hundreds of _____ of science fiction are published each year in our country.
----Are you sure that he is able to do the work well? ---- _______ he could give his mind to it.
It’s said that there are plenty of hotels in that town. There be any difficulty for you to find somewhere to stay .