词汇：根据句意填入一个恰当的单词完成句子。

1. What is your _________way to learn more English?

2. It doesn’t _________if you can’t understand spoken English.

3. Mei often _________mistakes in grammar.

4. Li Hong decided to_________lots of grammar notes in every class.

5. Her English improved when she started lots of_________practice.

定向天线的增益是15dBd，换算成dbi是（）。