Answer:
convex lens
Explanation:
because when parallel rays of light pass through a lens are brought together through a lens
Answer:
because of factories and cars and smoking
Explanation:
Answer:
Embedded in the lipid bilayer are large proteins, many of which transport ions and water-soluble molecules across the membrane. Some proteins in the plasma membrane form open pores, called membrane channels, which allow the free diffusion of ions into and out of the cell.
Answer:
refrain from using or disposing of (something); retain for future use.
Explanation:
The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.