He likes to take a walk in the park at dusk.

He is spending a lot of time on experimental research.

He is facing many difficulties due to gender identity disorder.

Research on cold fusion is still controversial.

It is reported that North Korea has conducted another underground nuclear test.

The number of nuclear-armed countries is increasing worldwide.

The caudate nucleus is a part of the brain that plays an important role in motor control.

The amygdala is a part of the brain that controls our emotions.

He is an expert in nuclear physics and has won many awards in the field.

The development of fusion reactors could potentially be the key to solving future energy problems.