找出每组单词中不同类的一个。
( )（1）A. fifteen B. cat C. bird
( )（2）A. sixteen B. big C. twenty
( )（3）A. short B. seventeen C. eleven
( )（4）A. father B .mother C. eighteen
( )—Thank you.
—__________.
| A．That’ s right | B．All right |
| C．Not thank | D．That’ s all right |
( )—Is this watch__________?
—No， it isn’ t. It’ s__________.
| A．your， his | B．yours， his | C．you， his | D．yours， she’ s |
( )What’ s__________the picture?
| A．in | B．after | C．over | D．about |
( )—Is her sister a teacher or a student?
—_____________.
| A．No， she’ s a teacher | B．No， she isn’ t a teacher |
| C．She’ s a student | D．Yes， she’ s a teacher |
( )__________look__________the blackboard.
| A．Let， at | B．Let’ s， at | C．Lets， like | D．let， on |