input: OPTIONS:
- trivalent bonds
- wavefunction double bonds
- gravitational double bonds
- covalent double bonds Now, answer this question: Q: Bond lengths are intermediate between covalent single bonds and what? A:
A:
output: covalent double bonds

input: OPTIONS:
- moment radiation scale
- direct magnitude scale
- moment identification scale
- moment magnitude scale Now, answer this question: Q: What scale measures the total energy released by an earthquake? A:
A:
output: moment magnitude scale

input: OPTIONS:
- accumulation
- over fishing
- pollution
- extinction Now, answer this question: Q: An estimated 99 percent of the species that have ever lived on earth no longer exist, showing that what event is common? A:
A:
output:
extinction