きのう ___ ___ _★_ ___ ました。

Translation: Yesterday, I read a book at the library. - Sentence Construction Strategy: 1. The final verb ending is 'ました' (past polite). The verb stem 'よみ' (from よみます / read) connects directly to 'ました', forming 'よみました' at the end. 2. This leaves '本を' (book + object particle), 'で' (at - location particle), and 'としょかん' (library). 3. Location marker 'で' must succeed the noun 'としょかん' -> 'としょかんで' (at the library). 4. The object '本を' must sit before the verb 'よみました'. 5. Full order: きのう [としょかん(2)] [で(1)] [★ 本を(0)] [よみ(3)] ました。 - Star position contains: 本を (Choice 1).