Through / Threw
Through is a preposition, as in "Superman can see through walls." Threw is the past tense of throw, as in "Superman threw several criminals into space before he remembered that humans can't breathe there." It's understandable how the mistake would be made, especially since the pronunciation of "ough" is the point at which the English language has a mental breakdown.
Wander / Wonder
To wander is to roam aimlessly, as in "Superman wandered through the ruins of a moon colony." This is not the same as wonder, which, when used as a verb, means to ponder or consider. For example, "Superman wondered what happened to those nuclear missiles he diverted into space." I usually see people spell 'wander' with an 'o,' and rarely see this mistake the other way around. This is reasonable, because the 'a' in wander makes a sound usually associated with 'o's. Here's a simple story to help you remember which is which: Superman destroyed the TV satellite, so I missed the end of the game. I wonder who won?
Past / Passed
Passed is the past tense of the verb pass. Example: "Superman passed by a wig shop that was being robbed; he didn't stop to help." The past is that point in time before the present and even farther before the future. Example: "Superman has an unpleasant past with bald people." This is an easy mistake to make, due to the similarity in pronunciation and, often, meaning. If the word you're looking for is a verb, it's probably passed, if it's an adjective or a noun, it's probably past.