--- The snowstorm caused great damage to this area.

--- Exactly, the economic _______ it caused reached 20 billion.

A．loss

B．effect

C．suffering

D．debt

推移可弯曲刮板输送机时，严禁按（）的顺序推移。

A．由机头向机尾

B．由机尾向机头

C．由中间向两头

D．由两头向中间