⒈在人行道上等待____
⒉当心,提防____
⒊遵守这些规则____
⒋过马路____
⒌红灯____
⒍在马路上保持安全____
of us has to have our temperature taken when we get in school every morning.
一节干电池的电动势为1.5V,这表示( )