In the fragments of the text: “they may lose the desire to master whatever task you are asking them to do” (lines 12-13) and “then you have to do more than just present lessons in the app” (lines 18-19), the verb forms in bold express the ideas, respectively, of 
In the sentence of the text: “However, if you want people to continue using the app, and use it frequently and often, then you have to do more than just present lessons in the app” (lines 17-19), the connector However can be replaced, without any change in meaning, by 
The failures of Latin American education systems have been pointed out by
Based on the meanings in the text, the boldfaced verbal expression describes the same as the verb in:
The term over in – “Asphalt over concrete” – that’s the standard. – means that
Considerando o contexto, o termo “heat exchanger” pode ser corretamente traduzido por
No âmbito do texto, a melhor tradução para o termo excelled in, dentre as apresentadas, é:
Considerando o contexto, o termo nothing to do tem o significado apresentado em:
No texto, a expressão and so on pode ser substituída, sem perda de sentido, por:
No texto, o termo aware tem o significado de
