1、The s______ "THIS SIDE UP" is often seen on a box.2、Don't

1、The s______ "THIS SIDE UP" is often seen on a box.2、Don't throw r____ everywhere.You should put it in the dustbin 3、We should make our c______to protecting our environment 4、Children should make ____ for old people in a bus A、room B、a room C、rooms D、the room 5、swimming is____in summer A、a great fun B、great fun C、 great funs D、great a fun 1、求x取何值时,下列式子有意义 根号下x-2x+5 3、若x、y为实数且y=[(根号下x-1）+（根号下1-x）]+1/（x-1）,求根号下x-6y