Focus when used as Verb bears different meanings. But the meaning it conveys here is “to concentrate" For example, (i) I am so tired I can’t focus (on anything) today. (ii) Please focus your minds on the following problem. Appreciate (Verb) means understand and enjoy (something); value highly, understand (something) with sympathy. increase in value. For example; (i) You can’t fully appreciate foreign literature in translation. (ii) I really appreciate a good cup of tea. (iii) I appreciate your problem, but I don’t think I can help you. (iv) Local property has appreciated (in value) since they, built the motorway nearby. So, we can use appreciate in the first gap and focus in the second gap to make the sentence meaningfully complete