【单选题】以下有关膜的不对称性描述中,正确的 是: ( )
B.
人红细胞膜脂中 磷脂酰胆碱 在外侧单层中含量较内侧单层高
C.
人红细胞膜脂中鞘磷脂在内侧单层中含量较外侧单层高
【单选题】广域网是跨越很大地域范围的一种计算机网络,下面叙述正确的是
A.
广域网是一种公用计算机网,所有计算机都可无条件地接入广域网
B.
广域网主干通常都使用自建的专用通信线路,数据传输速率很高
【单选题】The phrase 'day care' in Line 8, Para. 1 probably means ______.
【单选题】下面的方法,当输入为1的时候返回值是多少?() public static int getValue(int i) { int result = 0; switch (i) { case 1: result = result + i; case 2: result = result + i * 2; case 3: result = result + i * 4; } return result;...
【单选题】《招标投标法实施条例》规定,投标人在招标文件要求提交投标文件的截止时间之前撤回投标文件的,招标人应当自收到投标人书面撤回通知之日起( )日内退还。
【单选题】High clouds are composed primarily of ice crystals, whereas low clouds are composed primarily of water droplets. This difference is most likely because the average air temperature at altitudes from:
A.
0 km to 3.2 km is at or below 0°C, whereas the average air temperature at altitudes from 3.2 km to 6.0 km is above 0°C.
C.
0 km to 3.2 km is at or below 0°C, whereas the average air temperature at altitudes from 6.0 km to 16.0 km is above 0°C. C.0 km to 3.2 km is above 0°C, whereas the average air temperature at altitudes from 3.2 km to 6.0 km is at or below 0°C.
D.
0 km to 3.2 km is above 0°C, whereas the average air temperature at altitudes from 6.0 km to 16.0 km is at or below 0°C.
【单选题】( )是饲料中存在最普遍、最严重的一种霉菌毒素,它可通过食物链对人体健康造成危害。