science-presentation: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/science-presentation - from package: science-presentation

You may install the required package with command apt-get install {package}

Error in other languages:
science-presentation: bevel nie gevind nie
science-presentation: comandă negăsită
science-presentation: comando não encontrado
science-presentation: commande introuvable
science-presentation: command not found
science-presentation: käsku ei ole
science-presentation: không tìm thấy lệnh
science-presentation: komanda nerasta
science-presentation: Kommando nicht gefunden.
science-presentation: kommandot finns inte
science-presentation: komut yok
science-presentation: nie znaleziono polecenia
science-presentation: níor aimsíodh an t-ordú
science-presentation: no se encontró la orden
science-presentation: no s'ha trobat l'ordre
science-presentation: opdracht niet gevonden
science-presentation: parancs nem található
science-presentation: perintah tidak ditemukan
science-presentation: príkaz nenájdený
science-presentation: příkaz nenalezen
science-presentation: команда не найдена
science-presentation: командата не е открита
science-presentation: 命令找不到
science-presentation: コマンドが見つかりません