What is positively charged part of the nucleus

According to your text, the best way to reduce the number of germs is by ventilating spaces and a. cleaning all toys, books, and materials every day. b. keeping all potentially sick individuals out of the center. c. minimizing strenuous physical activity among the children. d. cleaning, sanitizing, and disinfecting surfaces and materials.

During the first month of development, how many layers of cells make up the embryo? a. 1 b. 2 c. 3 d. 4

Can someone give me a hand with this one.