Rob’s teacher asked him to explain the purpose of the introduction in an opinion piece. Which sentence describes the introduction?
A. The introduction gives the opinion.
B. The introduction restates the opinion.
C. The introduction supports the opinion with reasons.
D. The introduction sums up the reasons for the opinion.

Em um acidente, um caminhão carregado de solução aquosa de ácido fosfórico (h3po4) tombou, derramando cerca de 24,5 toneladas dessa solução no asfalto. quantas toneladas de óxido de cálcio (cao) seriam necessárias para reagir totalmente com essa quantidade de ácido? 2 h3po4 + 3 cao → ca3(po4)2 + 3 h2o a. 14t b. 29t c. 42t d. 7t e. 21t

read this excerpt from president john f. kennedy’s inaugural address on january 20, 1961: in the long history of the world, only a few generations have been granted the role of defending freedom in its hour of maximum danger. i do not shrink from this responsibility—i welcome it. i do not believe that any of us would exchange places with any other people or any other generation. the energy, the faith, the devotion which we bring to this endeavor will light our country and all who serve it—and the glow from that fire can truly light the world. and so, my fellow americans: ask not what your country can do for you—ask what you can do for your country. my fellow citizens of the world: ask not what america will do for you, but what together we can do for the freedom of man. based on the excerpt, what is the central idea of this speech? a. to cultivate a sense of well-being among the american people b. to motivate people everywhere to uphold the freedom of humankind c. to motivate americans to strive for the development of their nation d. to foster a feeling of happiness and unity across people and nations

Which is the correct definition of an economy ?