№3. Choose the preposition. 1. Many animals are in/ under threat.
2. They adapted to/ in the dark conditions.
3. He was singing loudly to scare by/ off bears.
4. Wear more clothes instead of turning off/ up the heat.
5. They warned me about/ of his bad behavior.

3. Choose the preposition.
1. Many animals are in/ under threat.
The correct preposition in this sentence is "under". We use the preposition "under" to indicate a state of being threatened or in danger.

2. They adapted to/ in the dark conditions.
The correct preposition in this sentence is "to". We use the preposition "to" to indicate the direction or target of adaptation.

3. He was singing loudly to scare by/ off bears.
The correct preposition in this sentence is "off". We use the preposition "off" to indicate the action of scaring away or repelling something.

4. Wear more clothes instead of turning off/ up the heat.
The correct preposition in this sentence is "off". We use the preposition "off" to indicate the action of turning something off.

5. They warned me about/ of his bad behavior.
The correct preposition in this sentence is "of". We use the preposition "of" to indicate possession or association with something negative or undesirable.

I hope this detailed explanation helps you understand the correct prepositions in each sentence. If you have any more questions, feel free to ask!