（） provide the water to the pistons.
举一反三
- The rooftop solar water heaters provide ______ without consuming any fuel.
- 2. The government has to open the dams to provide more water for the people.
- The Hoover Dam was the way to provide power and water to dry regions in the east America.
- An advantage of aluminum pistons， when compared to cast iron pistons is （）.
- Which of the followings provide energy？ A: Fat B: Carbohydrate C: Water D: Protein E: Vitamins