IF I HAD KNOWN YOU WOULD COME, ______. A. I WOULD WAIT FOR YOU B. I...

Câu 45: If I had known you would come, ______. A. I would wait for you B. I would have waited for you C. I will wait for you D. I would not have waited for you Đọc kỹ đoạn văn sau và chọn phương án đúng (ứng với A hoặc B, C, D) cho mỗi câu từ 46 đến 50. People usually sing because they like music or because they feel happy. They express their happiness by singing. When a bird sings, however, its song usually means much more than that the bird is happy. Birds have many reasons for singing. They sing to give information. Their songs are their language. The most beautiful songs are sung by male birds. They sing when they want to attract a female bird. It is their way of saying that they are looking for a wife. Birds also sing to tell other birds to keep away. To a bird, his tree or even a branch of a tree is his home. He does not want strangers to come near him, so he sings to warn them. If a bird cannot sing well, he usually has some other means of giving important information. Some birds dance, spread out their tails or make other signs.