Answer;
-Complex sentence
Explanation;
-Complex sentences are sentences that contain an independent clause and at least one dependent clause.
-An independent clause has the ability to stand alone as a sentence. It always makes a complete thought. A dependent clause cannot stand alone, even though it has a subject and a verb. In this case, the part, " Astronauts can experience bone loss, muscle weakness, and diminished heart function" is the independent clause, while , the part, "when they are exposed to environments with reduced gravity for a prolonged period of time", is the dependent clause.
