汽油的热值是4.6×107 J/ kg,完全燃烧210g汽油能放出 J的热量;若这些热量全部被水吸收,可使 kg水,从20℃升高到43℃ [水的比热容为4.2×103 J/(kg·℃) ]。
( ) My _____ are falling. A. book B. books C. pen
( ) But look ____ the balloons. A. in B. on C. at
()Come and _____ us! A.help B. helps C. helping
()I can _______ this box. A. carries B. carry C. carrying
()The balloons _____ flying away. A. is B. are C. do