1. Basic exercise: 1. Fill in the blanks for the time and distance of a train as follows: time (hours) 12345678… distance (kilometers) 80160240320400480560640 … In the table, the relevant quantities are () and (). 2. Judge whether the two quantities in the following questions are directly proportional, and explain the reasons. (1) The unit price of tomatoes is fixed, and the quantity and total price of tomatoes are purchased. (2) The price of Oriental Youth is fixed, and the number of copies and total amount of students subscribing to Oriental Youth are fixed. (3) the speed is constant, the time and distance of following the car. (4) The number of hectares of cultivated land cultivated by tractors per day is certain, and the total number of hectares and days of cultivated land. (5) The amount of cloth used to make a shirt is certain, and the total amount and number of pieces of cloth used to produce this shirt. (6) A person's age and her weight. (When answering a question, you can tell whether the two quantities are directly proportional, that is, whether the quotient of the two numbers is certain. )