Answer:
ok
Explanation:
Simple sentences contains on independent clauses ,also called main clause ,that stands alone.
Complex sentences contains an independent clauses plus one or more dependent clause.
Compound Sentences contains two independent clauses joined with the coordinating conjugation and comma .AND IT'S ENGLISH QUESTION NOT OF BIOLOGY.
You can tell if matter is conserved if the substance changes . If the substance changes then matter has been conserved .
Answer: The length of the cell in millimetres is 0.0015.
Explanation:
Given conversion :

Thus 
Given : Length of the cell = 1.5 micrometers 
To find: Length of the cell in milllimeters (mm)
Length of the cell in milllimeters (mm) = 
The length of the cell in millimetres is 0.0015.
Earth is a planet, Zero planets on earth