Last time you compared other people's definitions of development and noticed what each one counted and quietly left out. Today the class writes its own definition of sustainable development: one sentence you can stand over, stress-test, and keep.

Development on its own can mean growth, jobs, better services, or higher incomes. Adding the word sustainable does not just lengthen the sentence. It forces harder choices: needs now against needs later, gains here against costs elsewhere, and what can keep going without hollowing out the systems people depend on.

Use one of these situations (or a local equivalent your teacher allows):

• A new housing estate planned on a flood plain: homes for people now, higher flood risk later
• A data centre that brings jobs but warms a local river
• Cheap imports that undercut the town shop and its workers
• A wind farm on land the community uses for grazing
• A phone upgrade cycle that depends on mining far from here

Underline the part of your sentence that still stands and hand that phrase to your teacher. Surviving parts go onto the shared board list; the class then shapes one sentence everyone can live with. You will read that sentence back once at the end of this strand.

Look at the sentence the class just agreed.

Talk in pairs:

• Which test situation broke the most first drafts, and what did that expose?
• What did the word sustainable force you to add that a plain definition of development left out?

You will meet this definition once more at the end of the strand. No need to polish it further today.

Today you turned compared ideas of development into one class definition of sustainable development. You stress-tested drafts against real trade-offs, kept only what survived, and saved a shared sentence the class owns. That sentence is the yardstick you will hold up again at the end of this strand.