题目内容：

Put technology in the hands of someone like Elon Musk and it can send people into space, make a future of clean and renewable energy a reality, or build electric cars. Put in your hands, and it can help you achieve all sorts of things, from learning to code to learning a language.

Educational apps are becoming increasingly popular as a supplement(补充), and sometimes as an alternative

(替代物), to traditional education. Why? Well, for starters, it’s extremely convenient to learn on a pocket-sized device that you already carry around with you at all times. The best apps are also highly interactive and adaptive, coaxing you in and getting you hooked on learning.

But apps, just like textbooks and language lessons, are a medium through which a language can be studied. The way you use them will affect how successful you are. If you flick through a textbook and don’t dare say a word in your language lessons, you’ll make slow progress. The keen reader who repeats each exercise in the textbook and engages the teacher in the conversation will move ahead. So how do you ensure you get the most out of your app, and what should you consider before you install(安装) one?

Before that, a very quick introduction: I developed the following five points from my experience as both a language teacher and learner, and from working in startups in the field of language. I spent six years teaching in Germany and Spain as well as developing a video learning startup. However, I first came to language learning late. I started learning Spanish at 22, and was able to use Spanish and German freely by about 28. I’ve been using language apps for the last few years, and participated in two successful one-week challenges to go from zero to hero in Italian and French. If you’re interested, you can see the French challenge here.

So, just before downloading an app, here’s what you should think about…

1.We infer that Elon Musk is most probably __________.

A. an app developer

B. a language teacher

C. a professor at college

D. an engineer and tech company owner

2.What does the underlined part in Paragraph 2 probably mean?

A. Causing you to get tired of learning.

B. Encouraging you to interact with others.

C. Making you keep learning the language.

D. Providing new leaning methods for you.

3.What does the author want to show by giving the example of how one uses a textbook?

A. Doing exercise is important.

B. Different people learn differently.

C. Textbooks have become out of date.

D. We should use a language learning app correctly.