Solar energy is converted into electricity by -- and into heat by — and furnaces.

Explanation

To solve the question "Solar energy is converted into electricity by -- and into heat by — and furnaces," we can break it down step by step.

### Step 1: Identify the conversion of solar energy into electricity
- Solar energy can be converted into electricity using specific devices. The most common devices used for this purpose are solar cells and solar panels.
- **Answer for the first blank:** Solar cells or solar panels.

### Step 2: Identify the conversion of solar energy into heat
- Solar energy can also be converted into heat. This is typically done using devices like solar cookers and furnaces.
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