Some people haven’t realized something as common as _______to the sun for a longtime will do harm to their skin and even cause skin cancer

Unluckily, you couldn’t come to the picnic with us. It was so much fun there. You must come next time.—No, thanks. I don’t think I ______ any fun.

_______makes this shop different is that it offers more personal services.

Encouraged by my science teacher, I set about my studies on developing my product, _____I hope I will succeed in applying for a patent（专利）.

He had to retire(退休) early poor health.