What does it mean for a membrane to be selectively permeable?

only certain molecules are allowed to pass through.

the membrane is rigid and only allows water to pass through.

all types of molecules are able to pass into the cell.

the membrane is rigid and nothing can enter or leave the cell.

Only certain molecules are allowed to pass through

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

i hope this : )

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."