数字电影放映机开启电源后，所有状态指示灯不亮，最可能的故障部位是（） ["控制信号处理板","视频信号处理板","光引擎","供电空气开关未打开","开关电源有问题"]
An icebreaker displaying a flag hoist which consists of the code letters “WO” (Whiskey Oscar) is indicating that（）. ["icebreaker support is finished","icebreaker support is commencing","the icebreaker is icebound","the icebreaker is beset"]
某瓢虫种群中，有3种受温度压力选择的基因型个体（aa、AA和Aa），其适合度W分别是2、0.5和1。试问温度对上述基因型个体选择强度约为：（） ["0.5","0.75","1.2","3.5"]
全世界共有多少种语言？各主要语系的分布情况如何？
怎样计算卷烟人均消费量？
怎样计算卷烟市场容量？
