Answer: A physical change
Explanation: since the melted they are still Crayons. You can freeze it and it would still be a crayon. So it was only a physical change
Answer: Rivers
Explanation: Runoff from cars and other pollutants usually flow off of roads into rivers or streams that usually lead into bigger bodies of water such as oceans.
Helper T cells become activated by interacting with antigen presenting cells. and the second blank space is either cytotoxic t cells or B cells
Answer: False
Explanation:
Hemoglobin can be defined as red protein that transports oxygen to various parts of the body according to its need.
It does not transports the same amount of oxygen to all the tissues. Some tissues of the body might require more more oxygen and some cells might require less amount of oxygen.
It depends on the state of activity. It transports more oxygen to the tissue that require it the most.
Example: The skeletal muscles of the body require more oxygen and it can be more than 80% .
Hence, the given statement is false and hemoglobin does not releases the same amount of oxygen to each and every tissue of the body.
