a. 听得见的【电】 可闻的

◆记忆方法一：
词根词缀记忆法：audible听得见的；可听的（audi+ible能…的）,audi,audit=hear,表示“听”

audience/audial/audible/viewer/listener
记忆：
1. 词根audi表示“听”，audience [ 5C:djEns ] n. 听众, 观众 The audience were moved to tears. 观众被感动得流出了眼泪。
2. audial [`R:dIEl] adj. 听力的,(影响)听觉的 We need a great deal of audial practice. 我们需要大量的听力训练。
3. audible [ 5C:dEbl] adj. 听得见的 His heart beat is audible. 他的心跳听得见。
4. listener [ 5lisnE ] n. 听众 Some listeners wrote to the radio station in praise of her great work. 一些听众写信给电台表扬她的出色工作。
5. viewer [ 5vju:E ] n. 电视观众 How could the announcer make such a mistake in front of millions of viewers?播音员怎能在数百万观众面前出这样的差错呢？
另类阅读：
The computer can be both an audial aid and a visual one. It may help the speaker attract audience, including listeners and viewers.
轻松一刻
A teacher was explaining Wonder. He took an example: A man jumped from the 8th floor safe and sound. The teacher hoped the students would say Wonder, but one said Luck. The teacher was disappointed and said, “The man climbed to the 8th floor and jumped again, still unhurt." The student said, "Seldom." The teacher got angry and said, “The man climbed to the 8th floor once more, and jumped down … " Before the teacher finished, the student said, " Habit."