A:much practice is needed
B:one needs much practice
C:much practice is needed by one
D:one is needed much practice
关于内能及其利用,下列说法正确的是
若a2=b3=c7,且a﹣b+c=12,则2a﹣3b+c等于( )
下列诗句中,描述南方地区地理特征的是( )
下列说法中正确的是( )
现代生物技术的核心是克隆技术