R-r interval
[医] R-R间期(心电图)
🧩 词语组成解析
🗣️ 情景例句
He's planning a get-together
他计划办一个聚会
There is nothing which has not been bitter before being ripe.
事情在成功前没有不艰苦的。
In the afternoon, classes are over at 3:30, and I get home at about 4:00.
下午三点半下课，我大概四点到家。