She is well-qualified in typing and very efficient _____ her work. A. in B. at C. with Note: 1. If I change “her work” with “whatever she does,” do you think A would be the best answer? 2. Do you think B is the best answer because “her work” can be thought of as a location? 3. If I change “her work” with “numbers,” would you say C is the best answer? 4. Do you think in this case, there is some kind of rules or guidelines that tells us whether to use “in”, “at”, or “with”? Thank you