Connecting flight from San Francisco to Dallas

1) I wonder if your flight from Shanghai to San Francisco to Dallas is the same company or two companies? 2)PVG/ San Francisco, then you must go through the formalities of entering the United States in San Francisco. The situation is as follows: a, after arriving at San Francisco airport, enter the arrival hall (for you, you only enter in the direction of 1) b, take UA flight as an example, pass through the immigration bureau c, and hold the blue customs declaration form (there is 1 police to check your hands, so I won't say it here in special circumstances) d, and walk for about 20 meters. Pick up the checked baggage (there are 1 baggage carousel on both sides) e After picking up the baggage, show your passport and customs form to two policemen (usually two) at the exit, and then show them to the transfer station on the left (pay attention to the sign). 3) At the transfer station, check the original checked baggage again, and go to the terminal after the checked baggage leaves my sight. No matter how fast and convenient it is, it must be done. Generally, this process takes 10- 15 minutes. * * As for the two-hour connecting flight, if it goes well, there will be plenty of time. If you miss the plane, flying in America is not much different from taking a bus. You can take the next flight to Dallas. * * Do you hang your luggage directly? Please answer the question 1)? If it is an airline with 1 alliance, the luggage will be automatically connected to your destination city-Dallas.