3 (glass/make/from sand) Glass is made from sand.
4 (stamps/sell/in a post office) Stamps are sold in the post-office.
5 (football/play/in most countries) Football is played in most counties.
6 (this machine/not/use/very often) This machine is not used very often.
7 (what language/speak/in Ethiopia?) What language is spoken in Ethiopia?
8 (what/this machine/use/for?) What is this machine used for?