关系语言的特点是高度()，也就是说只要说明“做什么”而不必说明“怎么做”。用户不必请求DBA建立特殊的存取路径，存取路径的选择是由DBMS完成的。这也是关系模型的优点之一。
B
暂无解析
引起胸痛的呼吸系统疾病不包括
That is a ____ point of view. I don’t agree with you
We all ____ your coming to help us.
She was once a young country wife with chickens in the backyard and a view of _______mountains behind the apple orchard.
The Bent Pyramid outside Cairo __________ ancient Egypt ’s first attempt to build a smooth-sided pyramid.
Last March the __________ of a 19th century cargo ship was found by an underwater archaeological team.
He felt ____ of what he had done in school.
The first paragraph is intended to ________.
基层医疗卫生机构每年至少开展公共健康咨询活动的次数是
.If you have really been studying English for so long, it’s about time you _____ able to write letters in English.