What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass? What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass? a. They have both hydrophilic and hydrophobic regions. b. They are positively charged. c. They are completely hydrophobic. d. They are completely hydrophilic.

a chair, a bed, and a toothbrush

explanation:

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.