It is well known that the United States' population come from all over the world. The immigrants  can learn the language, English, to keep this country united, but it is unnecessary to change their culture for an American way of life. I believe that recent immigrants should learn English in order to live in the country. They should learn the "public language". If they don't learn English, they won't be able to communicate and do what they want. For example, my mother's friend came to the United States from Ecuador three years ago. She doesn't speak English. One day, her daughter, Anita, couldn't breathe. Anita didn't know what was going on, but she told her mother to call an ambulance. When her mother called the hospital, she couldn't communicate. The operator couldn't understand what Anita's mother was saying. Fortunately, her mother's sister arrived and called the ambulance. The doctor told her sister that if she hadn't arrived at the hospital on time, Anita could have died. A pill had gotten stuck in her throat. Immigrants should learn English to speak with the public, but they can also keep their language at home. The children of immigrants should learn how to speak their parents' language. It is very important to communicate with our relatives and family. If we learn English only and forget our private "language", we won't be able to communicate with our parents. For example, Florence, my co-worker, speaks English only. Her mother didn't teach her Spanish (her mother's mother language). Now, Florence can't communicate with her grandparents or other relatives in Puerto Rico. She has lost her mother's mother language, tradition and culture. Immigrants have the freedom to keep their culture and values. Immigrants should know where they come from and what their family's culture is. In this way, they can transmit it to future generations. In conclusion, immigrants should learn English in order to communicate with the public and to keep the country united, but they shouldn't give up their own culture. The author develops the passage mainly by   _  .
following the natural time order providing typical examples comparing opinions from different people presenting a cause and analyzing its effects