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问题 单项选择题

下列因子中，属于密度制约因子的是( )。

A．温度

B．降水

C．干旱

D．植物对光的竞争

答案

参考答案：D

解析： 密度制约因子是种群内部的因素，四项中只有D项符合，故选D。

单项选择题

Currently 94%of Web users use either Internet Explorer or Firefox．but recently somenew (71) have been developed that are beginning to attract attention．The browser Opera isbecoming very (72) because of its speed，it is currently the world’S fastest browsec andbecause it is much smaller (73) existing browsers(it can almost fit on a single diskette)．It canalso (74) the last web page you visited，so the next time you surf,you can start where you leftoff．And like the big two，you can get it for free；the catch is that you have to watch blinkingads in one comeL orpay$40 forthe ad—free (75) ofOpera．

A．beyond
B．SO
C．than
D．as
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单项选择题

患者确诊支气管肺癌1个月。现症见：咳嗽无力，少痰，痰中带血，神疲乏力，时有心悸，汗出气短，口干，午后潮热，手足心热，纳呆脘胀，舌质红，苔薄，脉细数无力。

其中医治法是（）

A.活血散瘀，行气化滞

B.祛湿化痰，清热解毒

C.养阴清热，解毒散结

D.益气养阴，化痰散结

E.行气化滞，清热解毒
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