①绷带____(A.bēn B.bēng)
②崭新____(A.zǎn B.zhǎn)
③骤然间____(A.zòu B.zhòu)
④土坑____(A.kēn B.kēng)
This chemical class is about the ______ of metals with oxygen and our teacher shows us how iron ______ air and water.
— ______, Mum.