What do we use water ________?

We must keep our school ________.

Fishing boats should stay in typhoon ________.

Scientists have made many slide shows ________ students.

Students and their teacher are ________ the Weather Observatory.

When the typhoon came, trees fell down, and ships and ships and boats ________ in the big waves.

We can see people going windsurfing in the sea when there is a _______.

Kitty and Danny have just put some pictures on a ________ board.

Careless people forget to put ________their barbecue fires in the countryside.

Early men found fire very ________ millions of years ago.