As soon as you hear the fire and emergency signal, you should ensure that the （）. ["ring buoys are thrown overboard","engines are stopped","fire pumps are started","life preservers have been issued to everyone"]
下列藻类中，具有世代交替的是：（） ["水绵","羽纹硅藻","衣藻","石莼"]
互感器式钳表是由（）组成的。 ["电压互感器和磁电系表头","电流互感器和磁电系表头","电流互感器和带整流装置的磁电系表头","电压互感器和电动系表头"]
在性别决定为XO类型的某种动物中，以下哪种可能是其体细胞中的正常染色体数目：（） ["雄性28","雌性35","雄性15","以上都不对"]
2014年顺风车的目标是帮助（）买不到票的人回家。 ["1100","5000","15000","十万"]
澳大利亚的动植物具有古老性、特有性特征的原因是什么？
