选词填空：[1] amy (a:plays b:am play c :playing) ping-pong on the weekeng.
[2]she (a:go b:goes c:went)to the library yesterday.
[3]what are you doing?------l'm (a:read b:reading c:reads)a book.
[4] let's (a:going b:goes c:go)to the park together next sunday.
[5] there (a:are,is b:is,has c:are,have)a clock on the table.the clock ( )three legs.