Complete subjects and predicates

Certain foods have been eaten for many centuries.What is the simple subject?

The Romans made the first pie with two crusts. What is the simple subject?

People stand outside to watch the parade. What is the simple predicate?

Panda babies are tiny enough to easily fit in the palm of your hand. What's the simple subject?

The people in the car are excited to go on the trip. What is the simple predicate?

The wolf is one of the most endangered animals in the world. What is the simple subject?

Tea leaves are eaten as a salad in Burma. What is the simple predicate?

A person's diet depends on available foods. What is the simple subject?

People ate potato chips during the time of the Civil War. What is the simple predicate?

Some people are afraid to fly in a plane. What is the simple predicate?

The gas tank is filled up to the maximum level. What is the simple predicate?

Wolves don't produce enough puppies to continue their species. What is the simple subject?

Ballooning can be very dangerous. What is the simple predicate?

Peanut butter was first used as a stomach cure in the 1800's. What is the simple subject?

Early colonists ate popcorn at the first Thanksgiving dinner. What is the simple predicate?