阅读下面材料，根据其内容和所给段落开头语续写两段，使之构成一篇完整的短文。续写的词数应为150左右。
Polly,
my stepmom, suggested the sweetest name to our pet dog: Mercy. We don't know
why she gave the strange name. We soon learned it was just what this new dog
would need.
My
parents' bad tempered dog would jump out of bed and go-go-go all day long. So
when they brought home a Christmas tree, they expected everything would be out
of order. However, to their astonishment, Mercy didn't seem to take any care.
She paid zero attention to the tree which suddenly grew in her living room. Nor
did she react to the fancy presents under it, including a wrapped box of
Milk-Bones.
Dad
and Polly were quite careful; they'd never had a dog that didn't force them to
move everything to higher ground as if they were expecting a flood. But Mercy
seemed to take no notice. He didn't take any glance at it at all.
A
few days before Christmas, Polly awoke early in the morning as usual. She
passed the dusty living room and then stopped in surprise. Glancing back into
the room, she saw that every last present was gone. Only the tree was still
there.
Had
they been robbed? Why hadn't Mercy barked? Where was she? Had the robbers taken
her away? Polly noticed scrap of ribbon (丝带)
on the floor, then bit of torn wrapping paper few feet away, some lights beyond
that. The clues all made a mark leading toward the back door.
Polly
put on the switch, bathing the backyard in light. The perpetrator's (肇事者)head lifted and froze. Alarm and guilt made her eyes wide. Oh, yes,
it was Mercy.
She
lay under her favorite tree in soft nest of shredde (碎片) wrapping paper, chewed-up boxes, and curling (缠绕) bits of ribbon. Presents, unpacked from their packages, were
spread over everywhere. Beautifully wrapped boxes had gaping holes. Pieces of
paper were mixed with the last remaining evidence of gifts. All the gift tags (标签) that could have been used as thank-you cards were destroyed.
Clearly
Mercy's self-control had failed.
……
As
for Thank-you cards, Mercy provided the answer.
