Here are the mistakes in each sentence:

1. **Sentence 1**: "more" (D) should be "the most" or simply "more dangerous" without "a."

2. **Sentence 2**: "raised" (B) should be "risen."

3. **Sentence 3**: "explode" (D) should be "explodes."

4. **Sentence 4**: "either" (A) is correct; the mistake is "to do" (C) should be "to do" (C) is correct as it is.

5. **Sentence 5**: "Finished" (A) should start with “After finishing” or similar to form a complete sentence.

So, the mistakes are in:
1. D
2. B
3. D
4. C (no change needed, but it's structure)
5. A