在信用评级机构对各类证券的评级中，以( )为基础的国债信用评级总是最高的。
A．国家主权
B．国家领土
C．国家信用
D．国家资源
参考答案：A
根据括号内的汉语提示，完成句子。
1. We have ______ (成功) in launching manned spaceships.
2. The Party is considering ______ (提供) the farmers with more care.
3. He is a little weak in _______ (发音).
4. There is no _______ (发现) in the research for the cause of the earthquake.
5. The students wrote best wishes on the blackboard with colored ______ (粉笔)
6. The scientist is a ______ (有创造力的) man.
下列说法，（）为箱式压力过滤机所具有的特点。
A.连续式过滤
B.间隙式过滤
C.过滤推动力较大
D.过滤推动力较小
