社会主义道德建设的核心为( )
A.集体主义
B.国际主义
C.为人民服务
D.爱国主义
参考答案:C
In the past 30 years China ______ great advances in the socialist revolution and socialist construction.
A.has made
B.have made
C.had made
D.having made
何谓出入沟、开段沟?堑沟的主要参数有哪些?