Comparison of adjectives (with (not) as ... as, than)

Billy is ​ (a)   his brother, because he is much younger.

• not as tall as
• taller than
• the tallest than
• as tall as

A cat is ​ (a)   a mouse. That's why cats can catch mice.

• faster than
• not faster than
• not as fast as
• as fast as

Oranges are​ (a)   lemons and they are ​ (b)   grapefruits, too.

• not as sour as
• sweeter than
• as sour as
• as sweet as
• not as sweet as
• more sour

Billy always tries to get home from school​ (a)   he can.

• as fast as
• not as fast as
• faster than
• not faster than

Ben and Josh are twins. This means that one is​ (a)   the other.

• as old as
• not as old as
• older than
• more old than

The (a)   trees grow in North America. They are called Sequoias.

The black jeans are​ (a)   the blue jeans. They are both $ 50,00.

• as expensive as
• not as expensive as
• more expensive
• expensiver
• not more expensive

My new bike is​ (a)   my old bike. I'm sorry I've sold the old one.

• not as good as
• as good as
• better than
• more worse than

Dave, can you run​ (a)   Billy? - Oh, yes! we both run the 60 m in 10.3 seconds.
But I hope I will be ​ (b)   he next year.

• as fast as
• faster than
• not as fast as
• the fastest
• more fast than

This article says that Elon Musk is​ (a)   anybody else in the world.

• richer than
• more rich
• as rich as
• not as rich as
• the richest