He remained silent and didn't say anything.

Even though he is a doctor, he doesn't take care of his own health. It's truly a case of 'physician, heal thyself'.

He is a bungler, so he is not good at detailed work.

He has an unserious attitude towards his work.

I'm troubled by his lack of seriousness.

Père David's deer, also known as the 'four unlike', is a species of deer native to China and is listed as an endangered species.

In genetics, linkage disequilibrium is a very important concept.

He always shows a frustrated attitude.

He always feels frustrated.

The success of this project is influenced by a lot of uncertainty.