1. Use the Zero Conditional to complete the sentences.

Here are the answers for exercise 1: 1) If he **has** (have) got a temperature, **call** (call) the doctor. 2) If you **take** (take) your umbrella if it **rains** (rain). 3) If you **heat** (heat) water to 100ºC, it **boils** (boil). 4) **Take** (take) a taxi if you **are** (be) in a hurry. 5) If it **is** (be) too late when you get home, I **don't wake** (not/wake) me up. 6) If you **put** (put) butter near the fire, it **melts** (melt). 7) If it **doesn't rain** (not rain), plants **don't** (not can) grow. 8) If you **smoke** (smoke), your skin **ages** (age) more quickly. 9) If you **heat** (heat) ice, it **melts** (melt). 10) People usually **feel** (feel) sick if they **eat** (eat) too much chocolate. **Explanation:** The Zero Conditional is used for general truths or habits. The structure is: If + Present Simple, Present Simple.