The Light List shows a lighted aid to navigation on the left bank. This means that the light can be seen on the starboard side of a vessel（）. ["ascending the river","descending the river","crossing the river","proceeding towards sea"]
为什么淡水鱼通常采用冷冻的方法贮藏？
If the action of the engine indicates that some of the cylinders are not firing, the ones affected may be determined by watching （）. ["the bad smoke","the smoky exhaust","the exhaust temperature","the peak pressure"]
根据《中华人民共和国工业产品生产许可证管理条例》的规定，工业产品生产许可证的有效期是（） ["5年","2年","1年","3年"]
一台三相异步电动机铭牌上标着220V/380V△/Y接法，当三相电源的线电压为380V时，该电机三相绕组连接方式为（） ["△","Y","Y和△均可","起动时Y，工作时△"]
简述接触期病原物的状态。
