Steam is a gas ____ forms when water boils.
that/which
A turtle is an animal ____ has a hard shell and can live in the water or on land.
that/which
A hammer is a tool ___is used to pound nails.
that/ which
A puzzle is a problem ____ can be difficult to solve.
that/which
An architect is someone ____ designs buildings.
who/ that
A comedian is someone ___ tells joke.
who/that
We are going on a route. It is very crowded in the mornings.
We are going on a route which/ that is very crowded in the mornings.
A pyramid is a structure ____ is square at the bottom and has four sides.
that/which
The passenger is from Argentina. He is sitting next to me.
The passenger who/that is sitting next to me is from Argentina.
The students are from Turkey. We are standing behind them.
The students who/ that/ whom/ - we are standing behind are from Turkey.
Plastic is a chemical material ____ can be shaped and hardened to form.
which/that
A carnivore is an animal ____ eats meat.
that/which
The guy is in my math class. He is talking loudly on his phone.
The guy who/that is talking loudly on his phone is in my math class.
An obstetrician is a doctor ___ delivers babies.
who/that