地壳含量最多的元素是()。 ["O","Fe","Al","Si"]
丛枝菌根arbuscularmycorrhiza
使用干粉灭火器时,首先拔下保险销,然后一手握紧喷嘴胶管,对准燃烧物体,另一手握住(),拉起提环,喷出粉末。 ["提把","虹吸管","压把","卡带"]
挡墙尺测量上宽的范围是()。 ["0.7-0.9","0.8-0.9","0.9-1.2","1.0-1.3"]
泡沫灭火器不宜扑灭()。 ["纸张着火","可溶性液体火灾","普通纺织物着火","可燃物体的初起着火"]
内生菌根endomycorrhiza