More （and） 90 percent of the calcium in the （human） body （is） in （the） skeleton.（）
A: and
B: human
C: is
D: the
A: and
B: human
C: is
D: the
举一反三
- The human skeleton has two divisions, ____________ skeleton (includes the head, the neck and the body trunk) and __________ skeleton(includes the upper and lower limbs).
- The human brain makes up about ____ percent of a human’s body weight.( ) A: 3% B: 4% C: 1% D: 2%
- The formation of human body current is mainly due to ( ). A: Potassium ion B: Sodium ion C: Potassium and sodium ions D: Calcium ion
- the human body is incredibly
- X-rays are harmless to the human body