Monkeys are similar to humans in many ways. For example, the (7)_________in a monkey family, such as between brother and sister, are often very close. A team of researchers studied a pair of bonobo monkeys called Kanzi and Panbanisha. (8)__________brother and sister team had learned how to make knives from stone. So the researchers decided to record how good they were. The researchers put a banana inside a box. Then they gave the bonobos what they needed to make knife. The (9)__________of this knife was to cut open the box to get the banana. Kanzi made a very good knife, but his sister Panbanisha could not. Kanzi saw his sister was feeling (10)__________and so he tried to give his knife to her. However, the scientists did not let him. Even in this situation, Kanzi knew what to do. When no one was looking, he put his knife (11)__________ his sister could easily find it, and she finally got her banana. To researchers, it was obvious from Kanzi's behavior that he really wanted to help his sister.