内燃机的动力性指标一般是指()。 ["有效扭矩","有效功率","转速"]
在下列实验步骤中,需用清水冲洗或漂洗以洗去药液的实验是() ["探究酵母菌的呼吸方式","低温诱导染色体加倍","观察DNA、RNA在细胞中的分布","叶绿体色素的提取和分离"]
扑灭甲类火的最好灭火剂是水。
计量检定结果必须做出合格与否的结论,并出具证书和加盖印记。()
A stretch where the channel changes from one side of theriver to the other is called a(). ["crossing","transit","transfer","passing"]
阴保外加电流控制范围是()至()。