For the first example, I would say "I took the stuff out of the container" -never say stuffs. It's always stuff. EXCEPT if you're using it as a verb in the 3rd person: "he stuffs himself at every meal, did you notice? He must feel so full!" In your second example, I would say "she dropped out of school because of lack of funds." "To drop out" is a very specific phrase that almost always applies to a person leaving school, or leaving a program. "She dropped out of grad school to start a company." Examples of "pull out": I thought I was going to drown, and then he reached in and pulled me out of the water. Thank God! Can you please reach in and pull the snake out of my drink? (Ok that was a silly example, but I did it just for fun). "Pull out" can also be used intransitively (ie without an object): I was planning to start a business with my brother but then he pulled out. (He pulled out of the deal or the business) "Pull out" also has a sexual meaning that you should be aware of. It is very common and it's actually the first thing I thought of when I saw "pull out"- when a man is having inter course, he can pull out before ejaculating. This is called "pulling out" and people know exactly what you're talking about.