边际消费倾向
参考答案:
边际消费倾向是指每增加一单位收入所增加的消费量。如果用MPC表示边际消费倾向,△C表示消费的变动量,△Y表示收入的变动量,则MPC=△C/△Y。
The famous musician, as well as his students, ____ to perform at the opening ceremony of the 2012 Taipei Flower Expo.
A.were invited
B.was invited
C.have been invited
D.has been invited
隧道竣工后,应在直线地段每( )处,测绘以路线中线为准的隧道实际净空。
A.50mm
B.70m
C.80m
D.100m