A、管径在1mm以下时称为细支气管
B、每个细支气管及其各级分支和所属肺泡构成一个肺小叶
C、细支气管分层不明显且杯状细胞和平滑肌减少
D、细支气管和终末细支气管无软骨支撑,其管壁平滑肌舒缩可调节肺泡内的气流量
根据气力输送的特点,降低动力消耗,节约能源是一个重要的研究课题,从经验中知,管道内径是关于能耗的重要参数。直观上看,当输送量一定时,管径过小,输送易阻滞,管径过大,虽输送畅通,但又造成能量的浪费。根据经验,把管径分成三组,各组的试验结果如下表所示,试用方差分析法比较各组的效果.
管径(mm) | 单位功耗 |
230 | 0.0308,0.0476,0.0504 |
250~260 | 0.0532,0.032,0.0218,0.028,0.028, 0.042,0.0336,0.042,0.042,0.028 |
280~320 | 0.07,0.07,0.0644,0.0312,0.0756,0.0756, 0.07,0.0588,0.0588,0.042,0.0308,0.0364, 0.0448,0.21,0.154,0.1064,0.1288,0.112, 0.1064,0.1288,0.0756,0.0644,0.0504,0.0644, 0.0504,0.0308 |
在Word中,若要求两个段落之间的间距小于一个空行的间距,最好的解决办法是()。
A设置字符格式来缩小段落之间的距离。
B设置段落格式来缩小段落之间的距离。
C在每两行之间用按回车键的办法。
D在每两段落之间用按回车键的办法。