____ (lucky), his second mother was very kind to him.
看拼音,写词语
zì zuò zì shòu
hǎi fēng hū xiào
____
bào yuàn
jiàn qǐ
习惯上用S表示( )
水蒸发变成水蒸气,该现象用分子的观点解释正确的是( )