我国的国民经济和社会发展规划体系由( )组成。
A．三级、三类规划 B．四级、四类规划C．三级、四类规划 D．四级、三类规划
参考答案：A
一个圆的周长是直径的3.14倍．______．
Wherever such an area is located, it will be immediately ______ by the enemy if armed forces are lacking.
A．taken
B．caught
C．occupied
D．kept
