對,Keep your voice down 有 聲音小點的意思
但是,反義句不可以說 keep your voice up
提高聲音的正確英語是 raise your voice
比如：can you raise your voice a little 你聲音能提高一點嗎?你能大聲點嗎?
也可以說 can you speak a little louder?
2.Keep your voice down 這里的down 是副詞.
3.她喜歡躺著看書 / 她喜歡躺在沙發(fā)上看電視
She likes to read lying down
She likes to watch TV lying on the sofa
4.她喜歡坐在沙發(fā)上打電話
She likes to sit on the sofa when talking on the phone
或
She likes to sit on the sofa when making calls嗯，謝謝幫忙啦She likes to watch TV lying on the sofa， lying 這里是表示動作同事進行嗎？謝謝She likes to sit on the sofa when talking on the phone 這個句子和上面類似，但是 這里的when不能沒有是嗎？謝謝She likes to watch TV lying on the sofa對， lying 這里是表示動作同事進行She likes to sit on the sofa when talking on the phonewhen 可以省略，但本人覺得 when 使句子更精確。