《关于党内政治生活的若干准则》规定，每个党员都必须严守党和国家的机密，并同泄露党和国家机密的现象作坚决的斗争。
参考答案：对
The children said ________ they ________ themselves very much. [ ]
A. if, enjoy
B. why enjoyed
C. where, enjoyed
D. that, enjoyed
导向钻进法施工时，应选用中等尺寸钻头的为（）。
A.硬黏土层
B.钙质土层
C.致密砂层
D.粗粒砂层
