Answer:
Closed system.
Explanation:
Robot is an closed system because there is no transfer of mass but transfer of energy occurs from robot to its surrounding. According to the definition of closed system, closed system is a type of system in which there is only transfer of energy occurs while in open system both mass and energy can be transferred from the system to their surrounding. So no mass transferred from the robot only energy in the form of mechanical energy is transferred.
The answer is D because its comparing and the other will just be listing
Answer: The virus weakens as time passes.
Explanation: The virus will weaken continuously during transmission, and will reduce its toxicity after several generations of transmission, without causing much harm to the human body.
Because the gravity of the sun keeps all planets in their orbits :3 hope I helped
