He is my online friend, and we play online games every day.

This bacteria can be killed by heat.

This food has been heat-treated to kill bacteria.

He prayed fervently for his sick friend.

He prayed earnestly for his sick mother.

Walking on the hot sand is very difficult.

She is good at playing the guitar, isn't she?

This furnace is very efficient.

Mom, will you make tea for me?

He proposed a new theory about the problem.