A. good B. careful C. orders D. recognizes E. owner F. certain G. easily

Do dogs understand us?

Be 【1】 about what you say around your dog. It might understand more than you think.

A border collie（牧羊狗）named Rico 【2】 the names of about 200 objects, say researchers in Germany. The dog also appears to be able to learn new words as 【3】 as a 3-year-old child. Its word-learning skills are as 【4】 as those of a parrot or chimpanzee（黑猩猩）.

In one experiment, the researchers took all 200 items that Rico knows and divided them into 20 groups of 10 objects. Then the 【5】 told the dog to go and fetch one of the items and bring it back. In four tests, Rico got 37 out of 40 commands right. As the dog couldn’t see anyone to get clues, the scientists believe Rico must understand the meanings of 【6】 words.