He is interested in the shape of the skull.

He started his journey towards the east.

We need to combine these data.

He was struggling every day to pass the exam.

He struggled to pass the exam.

He is considering investing in real estate.

Under the Firmiana simplex tree, he was reading a book.

His promotion was proper.

I think his promotion is proper.

Tō-on is one of the phonetic systems in Japan based on the phonetic system of China.