（）的结线图是类型图。

A、区段组合

B、单动道岔组合

C、列车信号主组合

D、方向组合

In a retail store, the average (arithmetic mean) sale for month M was d dollars. Was the average (arithmetic mean) sale for month J at least 20 percent higher than that for month M ？（）
(1)For month M, total revenue from sales was $3,500.
(2)For month J, total revenue from sales was $6, 000.

A．条件(1)充分，但条件(2)不充分．

B．条件(2)充分，但条件(1)不充分．

C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．

D．条件(1)充分，条件(2)也充分．

E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．