总体来看,我国改革开放前后经济波动状态的特征发生了一些改变,下列( )不属于改革后的经济波动状态特征。
A.振幅减小
B.峰位下降
C.平均位势提高
D.扩张长度缩短
参考答案:D
—Please go and say hello to your aunt.She’s in the living room now.
—She has arrived! But when ______ she ______?
A.will; arrive
B.did; arrive
C.had; arrived
D.has; arrived
下列物质不属于合金的是( )
A.青铜
B.硬铝
C.不锈钢
D.氧化铁