In what trimester does these happen

a sac called a placenta forms around the embryo and is connected to the embryo with an umbilical cord.
a) first
b) second
c) third

Type the correct answer in the box. spell the word correctly. which three categories of waste is savio promoting in his city? savio has been spreading awareness about the importance of proper waste disposal techniques. he has been visiting restaurants in his city and asking them to segregate waste into three categories, garbage, organics, and . so that it becomes easy to identify waste and treat them accordingly.

Mucous membranes.. a. cover or line external surface of body. b. line internal body surfaces that are in contact with the environment. c. produce antibodies to combat infection. d. secrete sweat, which has antibacterial enzymes.

Describe three ways in which technology has treat the flu