用适当的介词填空。(6分)
（1）We should be good________ animals.
（2）There are all kinds________ flowers on our planet.
（3）Mary's birthday is ________May.
（4）Pandas live  ________   the southwest  ________   China.
（5）Tom often goes to the library  ________   his friends.
（6）African elephants come________Africa.