四冲程内燃机工作时,机械能转化成内能的冲程是____ 冲程.
下列各句中划线的词语使用正确的一项是( )
____ ,浅草才能没马蹄。(《钱塘湖春行》)
根据句意及汉语提示,完成句子。(1)Unfortunately, my car ____ down when I went home.(抛锚)(2)He looked at me in ____ . (惊讶)(3)____ (安全) is important.(4)Have you ____ of the romantic tale? (听说)(5)In his ____ (三十),he began to teach.