DNA的基本结构成分为核苷酸,水解后形成()。
A.磷酸、五碳糖、碱基
B.磷酸、脱氧核糖、碱基
C.磷酸、核糖、碱基
D.以上三种都可以
E.以上三种都不对
参考答案:B
八角科植物花的花托形状为()。
A.柱状
B.球形
C.扁平
D.杯状凹陷
Allowance for fresh water for all freeboards other than timber 25mm. This wording is likely to appear in().
A.INTERNATIONAL LOAD LINE CERTIFICATE
B.PASSENGER SHIP SAFETY CERTIFICATE
C.CARGO SHIP SAFETY CONSTRUCTION CERTIFICATE
D.GENERAL DECLARATION