Arithmetic series
等差级数
🧩 词语组成解析
🗣️ 情景例句
About the quality of 500 cartons of tin food we ordered last time.
是关于我们上次定购的500箱罐头食品的质量问题。
Good words without deeds are rushes and reeds.
光说好话而不见行动，一文不值。
'What a day!' I thought.'It's raining again.
“鬼天气！”我想，“又下雨了。