Write four sentences about beach clean-up. Use the first conditional.

Step 1: Understand the first conditional structure (If + present simple, will + base verb).
Step 2: Formulate sentences based on the provided phrases and the first conditional.
Step 3: Construct the four sentences:

• If we don't put up posters, people won't know about the beach clean-up.
• If people don't know about it, they won't come and help.
• If they don't clean up the beach, it will be full of rubbish.
• If the beach is full of rubbish, it will be dangerous for green turtles.