I think they differ a bit in meaning.. I see it as this:
1.Garbage is a wrongly placed resource. = Some garbage is not placed where it should be. (Because of the use of wrongly).
2.Rubbish is a misplaced resource. = Rubbish is a resource we can use for much more than to just trash it. I think this one sounds ok.
3.Garbage is a resource that is put in the wrong place = Basically the same as the 1st one.
4.Dirt is said to be matter in wrong place.= This doesn't entirely make sense to me. Dirt would not be in the same "category" as rubbish/garbage, but more "dirt" on the ground/in the house/dirty clothes/etc.. While the other senteces are statements, this one implies more "rumour" (is said to be...).
1.In winter,people tend to catch A cold. = Sounds ok in my opinion, meaning in the winter time, most people can usually catch a cold.
2.In winter,people are tending to catch A cold. = "Are tending" is the present progressive tense. That doesn't add up with the 'in winter', which refers to _all_ winters in general, not this particular, right now.
3.In winter,people are apt to catch A cold. = This sounds so-so to me, not too bad. Meaning people are more prone to get a cold in the winter(which does make sense).
4.In winter,people are liable to catch A cold. = Same as the 3rd one; at risk or likely to catch a cold.
Hope this helped! :)