Answer:
Simple machines are all around us.
Our lives would not be the same without these machines.
Each window blind is operated by a pulley that closes and opens it.
A simple doorknob is a wheel and axle that allows us to open and close doors.
A rolling pin is another wheel and axle used to help prepare the dough for baking the crust of your favourite plantain tart.
Step-by-step explanation:
I have written the complete subjects in bold letters and underlined the simple subjects.
The subject is what the sentence is about. It tells us who or what performs the action expressed by the verb, or who or what is being described by the predicate.
The simple subject is the main word of the complete subject, usually a noun.
A complete subject is a group of words that contains the simple subject and words that modify (describe) it.
For example, Simple machines are all around us. The complete subject is simple machines. It is described by the predicate - are all around us. The main word of the subject is machines, which makes it the simple subject. We could say Machines are all around us, and the sentence wouldn't change too significantly. Simple is an adjective that modifies that noun machines, which is why it's also a part of the complete subject.