City buses are white and blue. Please board at the front door and pay the fare as you get

City buses are white and blue. Please board at the front door and pay the fare as you get on. The fare per ride is $1.50 for adults and $1.00 for senior citizens. The fare may be paid by cash, bus pass or multiple passes. Please pay the exact amount directly into the slot at the top of the fare box. Remember that bills are not accepted and drivers cannot make change for riders.
When you wish to get off the bus, please notify the driver in advance by pressing one of the buttons provided throughout the bus for this purpose. The bus may pass bus stops without stopping if no one is getting off or waiting to get on.
There are five subway lines in the city. The fare is set at five rates from $2.00 to $3.50 according to the number of predetermined    “price zones” traveled. To purchase the appropriate ticket, please check the fare on the boards installed above the ticket-selling machines in each subway station.
Pass through the automated ticket gates by inserting the ticket into the slot. When getting off the subway at a station beyond the validity of the ticket, pay the additional fare at a fare-adjustment machine.
【小题1】According to the information, all bus riders should     .A．exit from the back door B．let the driver know in advance if they want to get off C．ask the driver for changeD．pay according to a “price zone”【小题2】What is the lowest cost of a subway ride for an adult? A．$1.00.B．$1.50 .C．$2.00.D．$3.50.【小题3】 How can a rider determine the fare of a subway ride?A．It is automatically determined.B．It is always $2.00C．Fare-adjustment machines determine the fare.D．All fares are posted【小题4】This text mainly tells us     .A．how to use city buses and subwaysB．how convenient city buses and subways areC．how to pay the fare for city buses and subwaysD．how well city buses and subways are equippedB