Fifty cards, each with the word, its part of speech, a precise C1 definition, an example sentence, and up to three typical collocations on the back — carbon emissions, an endangered species, a delicate balance. Rate each card “I knew it” or “Still learning” and your ratings are saved automatically.

Eight gap sentences that ask for a different form of a word you have just met: environment becomes environmental, extinct becomes extinction, sustainable becomes sustainability, toxin becomes toxic, scarce becomes scarcity.

Ten pairs in the form a policy document would use them: cut emissions, a severe drought, coastal erosion, resource scarcity, end up in landfill, chemical fertilizer, water contamination, habitat restoration.

A mix of multiple choice and fill-in-the-blank, with an explanation after every answer, right or wrong. Your best score is saved automatically.

Degradation, contamination, scarcity and restoration are what a policy document writes where a conversation would say damage, dirt, shortage and repair. Knowing both registers, and choosing between them on purpose, is what separates C1 from B2 on this topic.

An ecosystem, a habitat and biodiversity are about relationships rather than individual plants and animals. That is why they take verbs like sustain, restore, threaten and upset, and why a delicate balance is the phrase that keeps coming back.

Conservation, preservation, degradation, restoration and sustainability all name a process rather than a thing. Essays on this topic are largely built out of them, which is exactly what the word-formation section drills.

After you finish the flashcard deck, it automatically rebuilds itself from just the words marked “still learning.” A short second pass on the hard ones is worth more than repeating the whole deck.

Write three sentences about one environmental issue near where you live, using this deck — emission, scarcity, conservation, sustainable. Local and specific always produces better sentences than global and general.