Mn giúp mình với mình cần gấp ạ ----- Nội dung dịch tự động từ ảnh ----- because they (2) f__1 happy. They People usually sing because they like music (1) express their happiness by singing. When a bird sings, however, its song usually means much more than that the bird (3) happy. Birds have many reasons for singing. They (4) S-- to give information. Their songs (5) their language. ---