现在进行时与一般现在时区别 — 英语词汇题

根据句意和中文提示，用动词的正确形式（原形或 -ing 形式）完成句子，注意一般现在时与现在进行时的区别。1. Look! Tom is r______（跑）on the playground now. 2. My friends p______（打）table tennis every Saturday. 3. Listen! The girls are s______（唱歌）in the music room. 4. We often w______（观看）football games on TV.