Paragraph 2
The researchers put
under the dogs'
to see if the dogs cried. When dogs saw their
after five hours of being apart, they cried. A
said he had never heard of
crying tears of joy. He said dog's tears might deepen their
with humans. He thinks dogs' tears make humans love their dogs
. He said: "It's
that dogs who show
...during human
would be cared for more."