O amplificador operacional (AMPOP) é um dispositivo versátil, com vasta aplicação em circuitos eletrônicos, por isso em Controle seu uso é muito comum. Tanto na modelagem de circuitos eletrônicos como na modelagem de Controle, as entradas do amplificador operacional assumem características ideais. Sobre o assunto, marque a afirmativa correta.

Another Defeat for Brazil’s Kids

SÃO PAULO, Brazil — This month, public school teachers from the state of São Paulo announced the end of their three-month-long strike — without any of their demands having been met. For the first time since it began, the strike reached the front page of a major newspaper; it had been mostly neglected until then. The headline declared: “Defeated, São Paulo’s Teachers Put an End to Their Strike.”

It was the longest teachers’ strike in the state. They maintained to the end their demand of pay parity with other college-educated professionals — which would ultimately have meant a 75 percent salary increase. This is a steep rise in public salaries, but the parity principle is part of the National Educational Plan, a law adopted last year with support from President Dilma Rousseff. According to that plan, parity is to be achieved by 2020.

The teachers also demanded smaller classes, with at most 25 students. The secretary of education stipulates a maximum of 40 students in high school classes, but last February, at the beginning of the school year, there were accounts of classes with 85 or 95 enrolled students. As if that weren’t bad enough, the state government shut down more than 3,000 classes this year, according to the teachers’ union for São Paulo State.

For a 40-hour workweek, professionals with a graduate degree who teach fifth to 12th graders earn a base salary of $770 a month, or $9,240 a year. And this is the best scenario; those who teach for elementary school (first through fourth grades) earn $8,100 a year. The extra hourly wage for teachers in the upper grades is $3.80, less than half what a fast-food worker earns in the United States. Let me stress the point: They are paid around $4 for teaching a whole class of 40 students for an hour.

The protesters also complain that the government does not follow a law that mandates one-third of the working hours to be spent in activities outside the class, such as marking exams and preparing for class.

(Available at http://www.nytimes.com/2015/06/26/opinion/vanessa-barbara-another-defeat-for-brazils-kids. Access 2015/07/07.)

Mark the statement that expresses the main intention of the author.

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Deus disse

Deus disse: Vou ajeitar a você um dom:

Vou pertencer você para uma árvore.

E pertenceu-me.

Escuto o perfume dos rios.

Sei que a voz das águas tem sotaque azul.

Sei botar cílio nos silêncios.

Para encontrar o azul eu uso pássaros.

Só não desejo cair em sensatez.

Não quero a boa razão das coisas.

Quero o feitiço das palavras.

Em relação ao sistema literário, marque a afirmativa correta.