下列各组词语中，没有错别字的一项是

I would appreciatevery much if you could send me a few copies of the mechanic design of yournew model. [ ]

Only 16 percent of China’s area ____ covered withforests, so ____of us should protect trees.

Do you know the boy under the tree_______ is playing with a dog/

下列词语中加点字每组读音都不一样的一项是（ ）