Roger: Reading a lot as a child causes nearsightedness— difficulty seeing things at a distance.
Louise: I disagree. Any correlation between nearsightedness and reading results from the fact that children who have trouble seeing things at a distance are likeliest to prefer those activities, such as reading, that involve looking at things close up.
Louise disputes Roger’s claim by

A．demonstrating that an absurd conclusion would follow if Roger’s claim were accepted.

B．arguing that what Roger claims to be a cause of a given phenomenon is actually its effect.

C．using an analogy to expose a flaw in Roger’s reasoning.

D．pointing out that Roger’s claim is self-contradictory.

E．(E) attempting to demonstrate that Roger uses the term "nearsightedness" in an ambiguous way.

液压节流阀应尽可能选用薄壁型节流口，其流量随（）影响很大。

A、黏度

B、温度

C、摩擦阻力

D、小空截面积