Rico is a dog who lives in Germany . His owners trained him from a young age to find his toys. When they say the name of a certain toy, Rico can find it. In fact, he seems to know the names of 200 toys! Some researchers in Germany wanted to test Rico. They put his toys in a room and then told him to go in the room and find a certain toy. Since nobody was in the room with Rico, he had no help from anyone finding the right toy. The researchers did this test forty times. Rico found the right toy thirty-seven times! Then the researchers tried something else. They put seven of Rico's toys in the room together with one new toy that Rico had never seen before. Then they told Rico to go into the room and get the new toy. This new toy had a name Rico had never heard before. Rico found the right toy seven out of ten times! Researchers cannot really say that Rico knows words or language. However, these tests seem to show that Rico can think about what he hears and think about what he knows. In fact, Rico seems to think and remember things as well as a three-year-old child. From these tests, animal researchers know one thing for sure. Rico has given them a lot to think about. Rico went into the room _ times to find a new toy he did not know. A) seven B) thirty-seven C) ten D) forty
C