Generally speaking, ellipses are unnecessary at the beginning of quoted sentences where words are left out. Think about the weaving of quoted material into your own paraphrased context. Sometimes only a few words within your sentence are in quotations. In such a case, as long as you are not changing the meaning of the original text, it is perfectly acceptable to pick and choose the parts you wish to quote and ellipses at the beginning or the end of quoted material are unnecessary. Consider the following (made-up) example:
Original quote: "I love Mark Twain's satire. He is one of my heroes in the literary world because he uses intelligence combined with humor to make his point." - John Smith
Use of quote with correct MLA format: Mark Twain's satire has earned him the status of "hero" in the literary world. One author claims to love him because of the way "he uses intelligence combined with humor" (Smith 89).
The only exception to the elimination of ellipses would be if you are quoting something that already includes ellipses in the original text. In this case, do put the ellipses in the quote to show it was in the original. If you need to omit words (from a text that includes its own ellipses) and therefore add your own ellipses, MLA suggests putting your ellipses in brackets [...] to show that they are added and suggest that you omitted words, rather than omissions from the original text.