23. Environmental experts are those who devote ______to______ nature and environment.

Underground railway is being built in Shenyang. We are sure to take the subway to ______ in the city in no time.

The design of this architecture has to _____ all ages and social groups, which should be made clear to whoever is to design it.

Finally the thief had to       he had stolen the valuable necklace

I am looking forward to _______ you again next month.

—What’s up? You look down.  —I have piles of papers ________, but I type so slowly.

Great attention must be devoted ________ agriculture(农业), especially in China,
______ population is the largest in the world.

It remains ______ whether Liu Xiang will take part in the next Olympics.

I don’t think the problem you referred to is worth______.

He is thinking of           his business while his father is strongly against it for fear of the further positive effect of the global economic crisis. .