The combustion of fossil fuels like coal, petroleum and other factory combustibles is a major cause of air pollution. ... Meanwhile, emissions caused by gasoline-burning vehicles – i.e. CO, CO², nitrogen oxides, particulates and water vapor – are also a significant source of air pollution.
I say Air Pollution
The three primary germ layers (called the ectoderm, mesoderm, and endoderm) are the primary layers of cells in the embryo from which all tissues and organs develop. Human pluripotent stem cells are also known as human embryonic stem cells.
The sewing needle should float in the water if placed on a horizontal angle if I remember properly.
I hope this helps in some way.
The most likely answer is a Nuclear Membrane.
