I think the correct answer among the choices presented above is option A. If you are new to an activity, it is better to <span> work at a slower speed for more days a week. In this way, you will be acquainted with the work you have and as time pass by, you will be more skilled and faster.</span>
B. its should be propped up against the wall
If the blood is carrying oxygen, the cell and the blood will have a sort of trade. The cells will give the blood the waste which will leave the body and the blood will give the cell oxygen which it needs to stay alive and continue to work.
