题目

右图为某同学用丝带扎紧上臂的示意简图。发现丝带下方（近手指端）的血管①膨胀，血管②变扁；丝带上方的血管③膨胀，血管④变扁。下列有关叙述中，正确的是A．血管①、④是动脉B. 血管②、③是静脉C. 血管①中血液的含氧量比血管③低D．血管④中血液的含氧量比血管②高  答案：C解析:略  . It is the test system, _____ the teachers, that is to blame for the heavy burden of middle school students nowadays. A. other than           B. or rather             C. rather than               D. more than