He was cutting down a tree.

I am thinking of a new marketing plan.

He signed my book.

Please calculate the value of the sine, which is one of the trigonometric functions.

He signed the contract.

His son was born with the disease of imperforate anus.

This plant forms a capsule.

His new novel is being evaluated as a good work.

He is good at making new fonts.

He is working on the creation of a new font.