It can be inferred that railroad refrigerator cars came into use _________ . A. before 1860 B. before 1890 C. after 1900 D. after 1920Đoạn văn61/97It can be inferred that railroad refrigerator cars came into use _________ .before 1860before 1890after 1900after 1920Giải thíchChọn B