ubuntu package download/install, architecture type selection

-. download

#] sudo apt-get download package-name

eg. #] sudo apt-get download lib-ncurses5-dev

-. install

#] sudo dpkg -i package-nameXXXX.deb

eg. #] sudo dkpg -i libncurses5-dev_5.9+20140712-2ubuntu1_amd64.deb

-. download and install

#] sudo apt-get install package-name

eg. #] sudo apt-get install lib-ncurses5-dev

-. architecture type selection

#] sudo apt-get install package-name:architecture-name

eg. #] sudo apt-get install lib-ncurses5-dev:arm64