电工证有效期几年

开头是g结尾是t的单词,四个字母 兔子喝生水还是开水?花鸟市场买来的小白兔,要给喝生自来水还是给喝温的开水啊? 测定BOD5时水样浑浊要不要过滤 开水能加生水一同喝吗? 测BOD5时水样量不够测DO啊?怎么办我最近在看GB,BOD5培养一个水样大概需要250-300mL,培养完了,要测DO了.可是用碘量法测定测它的DO就先需要50mL测定有没有还原性或者氧化性物质,如果有,我就需要 喝生水好还是喝开水好?为什么有人提倡喝生水呢? 如何降低水样BOD5 开水和生水能不能一起兑着喝 怎样区分酸碱盐!(电离的角度)有更简单的区分方法也可以 请问初中酸碱盐中解离与离解与电离区别是什么? 英语翻译Telecommuting is a new form of work afford those previously unable to work,such as fathers with children,the chance to work while remaining at home. 请问煮白米饭是用生水好还是开水好?煮白米饭用生水煮会比开水更加耗电,可是从健康及营养的角度来讲,到底是用哪种水煮比较好呢? tree-planting Day is (March 12th).括号部分提问 酸菜鱼煮的时候用生水还是开水 用march,day,is,tree-planting,12th,on和句号组成一句话 tree-planting Day is March 12th.翻译 tree-planting Day is (March 12th).括号部分提问翻译 我国哪个城市的空气比较好? 如何知道物体排开液体的体积受到的重力?V排液是? 《假如没有灰尘》告诉了我们怎样的哲理?没有灰尘,地球上的水会怎样? Doing work means mobbing a body through a distance by a force什么意思啊? Kobe Doing Work怎么翻译? work on to do和work on doing有这种说法吗?和go on to do ,go on doing at work ,be work doing 区别 march 12th is tree ___(plant)fsy in china Chinese Tree Planting Day is on March 12th改为特殊疑问句 谁能推荐几本关于写人生的书? done 和being done的区别都是表示被动的分词,该怎么区别请简便说明 The work is ______(most) done almos mostly怎么区别 We being League member,the work was well done翻译 保温材料硅酸铝是否导电 the teacher wants the work _____at once.A,doing B,being done c to be done d,to have done为什么选C呢,怎么不选A,