石灰是以天然石灰岩为主要原料(含90%以上碳酸钙),在800~1000℃的温度下煅烧,所制得的以氧化钙为主要成分的一种气硬性胶凝材料。
参考答案:对
—Oh, this is really a big shop. Do you know when it _______?
—Last year. [ ]
A. built
B. was built
C. has built
D. has been built
我国金融组织体系以( )为领导。
A.中央银行
B.商业银行
C.中国人民银行
D.政策性银行