What does Marley's comparison of kindness to the first green grape of summer mean?

Now you will do a special kind of problem. you will use the blue boxes below to put events of the story "the baby-sitter" in correct order. each blue box has seven sentences inside it. click the first blue box until you see the first thing that happened in the story. then go on to the next box and the next thing that happened. the last thing that happened should be in the last box. you may need to look back at the story to you remember. if you change your mind at any time while you are working the problem, you can return to a box and click to find a different sentence. when you are all finished, you will be able to read down the list of sentences and see all seven events from the story in the right order. mary jo began to read the alphabet book. mary jo couldn't move. mother asked mary jo to baby-sit. jimmy was very quiet. he had fallen asleep. jimmy to read the book. mother said, "you are a very good baby-sitter." mother picked up sleeping jimmy.

In the poem, collins suggests that memories do what as people age

Which summarized story is most likely a myth?