<p>They'll "accept" anything you submit. But if you look at their sites' guidelines you may learn more. For instance, Yale covers this question explicitly. It's up to you to decide how you want to follow it:</p>
<p>"Who should write my teacher recommendations?</p>
<p>It is important that your recommenders be teachers who can write about your recent academic work in rigorous academic subjects. We strongly encourage students to ask 11th and 12th grade teachers to write for them. Given Yale's extremely competitive applicant pool, it is probably a mistake to ask a favorite ninth-grade teacher to write, or to seek out a coach or chorus director as a recommender unless he or she has also taught you recently in an academic course.</p>
<p>Yale does not specify that the recommendations come from teachers of particular subjects. It is a good idea, however, to have the two letters come from teachers of different subjects. Choose teachers who know you well and who can give us a sense of both your academic and personal strengths. "</p>
<p>You and all others who are subjecting yourselves to applying to the ultra selectives are to be commended. If you're very serious about it and putting your best foot forward, then I'd highly recommend you to follow Yale's advice for all the schools you've listed. They want RECENT teachers.</p>
<p>I think the majority of teachers you'd consider can help your chances if you prep them. Don't just ask for a rec and hand them the materials. Ask to sit down and discuss your accomplishments in that teacher's class. Readers most appreciate very specific anecdotal accounts. The more cogently your teacher can express one or two instances of these will allow you to present yourself in the most favorable light. smart: it's a tough choice but I think I'd lean on prepping my APUSH teacher.</p>