Finding information in today’s world is easy．The      is how you can tell if the information you get is useful or not．

A．ability

B．competition

C．challenge

D．knowledge

下列疾病中弛张热不常见的是（）。

A.风湿热

B.重症肺结核

C.败血症

D.急性肾盂肾炎

E.化脓性疾病