荧光抗体染色技术中,抗体与荧光素结合是依靠()。
A.范德华力
B.共价键
C.氢键
D.静电引力
E.二硫键
参考答案:B
解析:抗体与荧光素共价结合。
It has been announced that students shall remain in their seats until all the papers _____.[ ]
A. will be collected
B. were collected
C. have been collected
D. have collected
数据库管理系统通常提供授权功能来控制不同用户访问数据的权限,这主要是为了实现数据库的______。
A.可靠性
B.一致性
C.完整性
D.安全性