How the word "かせい（火星）" is translated into English
いつか人がかせいに住める日が来ると思いますか。
かせいは赤く見えるので、すぐに分かります。
ニュースでかせいの新しい写真を見ました。
"かせい（火星）" is in the lesson "Space" (Level 25), along with 15 other useful words. LinDuo has 180 topic lessons like this one, 2,379 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.
