Although wolves and dogs are closely related， they show some striking differences. Austrian Scientists have undertaken experiments that suggest that wolves observe one another more closely than dogs and so are better at learning from one another. The scientists believe that （A）

c among wolves is the basis of the under-standing between dogs and humans.

The scientists found that wolves are considerably better than dogs at opening a container， providing they have previously watched another animal do so. Their study involved 14 wolves and 15 dogs， all about six （1） m old， hand-reared and kept in packs. Each animal was allowed to observe one of two situations in which a trained dog opened a wooden box， either with its mouth or with its paw， to gain access to a food reward. Surprisingly， all of the wolves （2） m to open the box after watching a dog solve the puzzle， while only four of the dogs managed to do so. Wolves more frequently opened the box using the method they had observed， whereas the dogs appeared to （B） c randomly whether to use their mouth or their paw.

To exclude the possibility that six-month old dogs fail the experiment because of a delayed physical or cognitive development， the researchers （C） r the test after nine months. The dogs proved no more successful at opening the box than they were at a younger age. Another possible （3） e for the wolves' apparent superiority at learning is that wolves might simply be better than dogs at solving such （D） p . To test this idea， the researchers examined the animals' ability to open a box without prior demonstration by a dog. They found that the wolves were rarely successful. Their problem-solving capability really seems to be based on the （E） o of a dog performing the task. The wolves watched the dog very closely and were able to apply their new （4） k to solve the problem. Their skill at copying probably relates to the fact that wolves are more dependent on cooperation with conspecifics（同種個(gè)體）than dogs are and therefore pay more attention to the actions of their partners.

During the process of domestication， dogs have become able to accept humans as social partners and thus have adapted their social skills to include interactions with them， gradually losing the （5）

a to learn by watching other dogs.

（A， B， C， D， E FOR CROSS， 1， 2， 3， 4， 5 FOR DOWN. The first letters of the absents were given）