阅读下面对话，掌握其大意，并根据所给的字母的提示，在标有题号的横线上写出一个英语单词的完整、正确形式，使对话通顺
Here is a conversation between a
baby snail and his mother, which 1..t______ me deeply.
Baby snail: “Why was I born with a 2..s______
that grew so hard and so heavy?”
Mother snail:
“Because we do not have bones to 3..s______ us. We can only crawl and move 4..s______,
so we get a shell to protect us.”
Baby snail: “The
caterpillar（毛虫）has no bones either, nor can she move quickly. Why can she go
without a shell?”
Mother snail:
“That’s because a caterpillar will become a 5..b_______. She can fly high to
sky, and the sky can protect her.”
Baby snail: “But
the earthworm（蚯蚓）6..c______ like us. He has no bones, nor can he turn into a
butterfly. Why does he not 7..c______ a hard and heavy shell?”
Mother snail: “He
can drill a hole into the ground to protect himself.”
Baby snail:
(Bursting into tears) “What a 8..p______! We have no 9..p______ from either the
sky or the ground.”
Mother snail:
“That’s why we are 10..g______ with a shell. We don’t need to depend on the sky
or the ground for protection. We depend on ourselves.”