The total output value of agriculture （)4 times since the introduction of the new technique.

A.EXEC proc_stu @sum OUTPUT,64,78

B.EXEC proc_stu @sum OUTPUT,@total output,78

C.EXEC proc_stu @sum OUTPUT,604

D.EXEC Calculate @sum OUTPUT,@total output

A.The total grain output in 2019 more than quadrupled the 2009 figure, or an average increase of 3.1% a year.###SXB###B.The total grain output in 2019 more than quadrupled, comparing the 2009 figure, or an average increase of 3.1% a year.###SXB###C.The total grain output in 2019 more than quadrupled the 2009, compared with its output figure, or an average increase of 3.1% a year.###SXB###D.2019 and 2009 were in comparison that the former quadrupl

A.The total grain output in 2019 more than quadrupled the 2009 figure, or an average increase of 3.1% a year.###SXB###B.The total grain output in 2019 more than quadrupled, comparing the 2009 figure, or an average increase of 3.1% a year.###SXB###C.The total grain output in 2019 more than quadrupled the 2009, compared with its output figure, or an average increase of 3.1% a year.###SXB###D.2019 and 2009 were in comparison that the former quadrupl

A.is constant.B)is risin

B.is falling

C.is $2.00, $1.50, $1.33

A．average fixed cost．

B．average total cost．

C．average variable cost．

D．marginal cost．

A.total cost divided by the number of units produced

B.fixed cost divided by the number of units produced

C.extra fixed cost of producing an additional unit of output

D.extra cost of producing an additional unit of output

tal cost (ATC) curve and the average variable cost (AVC) curve？ The vertical distance between the ATC and AVC curves:

A)increases as output increases.

B)decreases as output increases.

C)increases and then decreases as output increases.

A．marginal cost．

B．average variable cost．

C．average total cost．

D．average fixed cost．

Marginal cost is the: （)。

A、total cost divided by the number of units produced

B、fixed cost divided by the number of units produced

C、extra fixed cost of producing an additional unit of output

D、extra average cost of producing an additional unit of output

E、extra cost of producing an additional unit of output