graphite

"My sister is painting her bedroom walls a cheerful yellow. "

"It requires great strength to lift heavy objects."

"Nuts in engineering are generally hexagonal."

"The countertop is a composite of recycled glass and concrete. "

"The bike chain was squeaking loudly, so I applied lubricant to it to make it run smoothly. "

"The project consists of three main parts. "

"Carbon exists as several allotropes, including diamond and graphite, which have very different properties despite both being made of only carbon atoms. "

"After sitting at the desk for hours, I felt a lot of stiffness in my neck. "

"She arranged the books on the shelf by color. "

"Asphalt, composed of oil and sand, is a widely used material for roads."

"The contractor used fibreglass insulation to help keep the house warm in the winter. "

"He reinforced the handle with a metal rod and a bit of tape."