The bottom quark plays an important role in particle physics.

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 bought six apples.

I'm looking forward to meeting my friends this weekend.

In physics, the charm quark is one of the six quarks.

Yu helped me with my homework.

It seems that this river is flowing backwards.