II.1: 1.T-"in 1850,a salesman in California..."
2.T-"six years later,Levin began making his pants with blue cotton cloth called denim"-six years later(6 nam sau) tính iwf năm 1850;begin+Ving/toV nên câu này đúng
II.2: 1.almost two hundred years ago-"the story of jeans started almost two hundred years ago"(line2,3)
2.because pants made of canvas were so strong-line 4,5-"in1850,a salesman in California began selling pants made of canvas....because they were so strong,"Levi's pants" became popular...." ở câu trong đoạn văn có từ "they" nên phải liên hệ vs cả mấy câu trước để có câu trl hoàn chỉnh
