The digestive system is critical to maintaining a healthy body because

a.
the digestive system make food taste better.

b.
the digestive system is the primary way the body obtains oxygen.

c.
the digestive system collects the nutrients needed by the body.

d.
the body expels all of its waste using the digestive system.

According to piaget, children have acquired the cognitive skill of conservation when they're able to a. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal. b. understand the viewpoint of other people. c. relate objects around them to their own needs. d. realize that the term heavy describes an object one way and the term big describes it another way. it is not b nor c. did this 2 x wrong..