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 
No contexto, o trecho “… a better way to develop, deploy, and manage data-tier applications” pode ser traduzido, mantendo-se o sentido, para: 
O texto informa que uma consequência do aumento de aplicações que utilizam banco de dados e da existência de hardware com baixo custo e alta capacidade de armazenamento foi 
Considerando o contexto, o termo grifado em “… new problems arise …” pode ser traduzido como: 
No segundo parágrafo, o termo while em – GOES satellites are owned and operated by the National Oceanic and Atmospheric Administration (NOAA) while the National Aeronautics and Space Administration (NASA) manages the design, development and launch of the spacecraft. – é corretamente substituído por
In the excerpt of the fourth paragraph – Paramagnetic properties are due to the presence of some unpaired electrons – the expression due to can be replaced, without changing its meaning, for
In the text, the word “current” (l.1) means
The word “actual” (l.24) is synonymous with
