Bring an umbrella with you__________ it rains.
Form their ________ on the top of the TV Tower, visitors can have a better view of the city.
Children need friends their own age to play with.
The ____________ shoes were covered with mud, so I asked them to take them off before they got into __________ car.
In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.
Hiking by oneself can be fun and good for health. It may also be good for ______ building.