He worked as a rear gunner in a fighter plane.

This problem is difficult, and I give up.

This handover is our new project.

The lar gibbon, with its long arms, moves quickly from tree to tree.

He is able to both talk and do, and can handle any job.

He boarded the fighter plane as a tail gunner.

He was my student, but now he has become so proficient that it can be said 'the student has surpassed his teacher.'

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

He is doing a special exercise to strengthen his flexor carpi ulnaris.

He is doing special exercises to strengthen his extensor carpi ulnaris.