阅读下面短文，从短文后各题所给四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
“How can I learn English well?” “This is a 1 many students may ask. In my opinion, the most effective(有效的) 2 is to learn lessons by heart. If you can recite the text and write it out, you will learn it pretty well. And if you can tell 3 your own words about 4 the lesson says, you are a very successful learner indeed. Your English will be quite perfect.
This is a difficult task. However, if you try to learn by heart only part of each lesson, you'll find it not so hard 5 you might have thought.
Learn this way, and you will 6 fast progress. Of course, writing is also necessary. It helps you a lot on your way to 7 in English studies.
It's equally(同样地) important to feel the language. You should laugh at English jokes and be 8 at bad news. When using English, try to 9 your mother tongue(母语). 10 helping you, your own language gets in your way. So, never try to learn English through putting every word into Chinese.
的方程
有实数解，则实数
的取值范围是 （ ）
