What two layers make it difficult for materials to pass through the cell membrane?

Megan is a three-year-old girl. every day, her nanny tells her a story. when her parents get home from work, megan tries to tell them the story. however, she can only retell a few parts of each story. she speaks in short sentences and often plays imaginary games. which type of developmental change is megan experiencing? a. social b. emotional c. physical d. cognitive

Which of the following is a health risk associated with ground-level ozone? a.cataractsb.skin cancerc.respiratory illnessd.all of the above

American college students invented football by combining what two sports?