They____very active together.

一个密封的罐子里有100克碘131，放置24天后，这个罐子里只剩下12.5克碘131．则碘131半衰期是____天．

根据短文内容，判断下列句子是否正确，对的涂（A），错的涂（B）。
    Kate is a little girl. She's only five. She is not at school. She doesn't know how to read or write. But her sister Mary is a student. She knows how to read and write.
    One day, Mary sees her little sister in the room. She is at the table. There is a pencil in her hand. She is writing. “What are you writing, Kate?” she asks. “I'm writing to my friend, Rose.” says Kate. “But how can you? You don't know how to write.” says her sister. “Well.” says Kate, “It doesn't matter. Rose doesn't know how to read, either(也).”
____ Kate doesn't go to school because she is too young.
____ Kate and Mary arefriends.
____ One day, Kate is writing to Mary.
____ Kate can't write.
____ Rose can read.

已知集合A={x|3x+x²＞0}，B={x|﹣4＜x＜﹣1}，则（　　）