人体内嘌呤核苷酸分解的终产物是()。
A.尿素
B.尿酸
C.肌酸
D.肌酐
E.甘氨酸
参考答案:B
解析:本题考查嘌呤核苷酸分解代谢,嘌呤核苷酸分解代谢的终产物为尿酸。
面嵌体洞型轴壁向方外展的角度应为()
A.0°~1°
B.2°~5°
C.6°~9°
D.10°~13°
E.14°~17°
Internet shopping is really _____________ when people are sure of its safety and security.
A.taking off
B.taking up
C.setting off
D.setting up