Please help answer the following questions.

1. It shows the different combinations of inputs that correspond to the same level of output. 2. An infinite number of sellers exist in this type of market. 3. It is a past expenditure that cannot be recovered or changed by any decision in the future. 4. A firm may only increase its output by increasing the quantities of all types of inputs, including the plant size. 5. A cost that involve actual expenditure or actual purchases. 6. It shows the different combinations of inputs a producer can afford in producing a specific quantity of goods or services. 7. This cost involves no obvious cash outlay. It is the value of the next best use of unremunerated input 8. It is an additional cost a firm incurs if it takes on a product line or service other than what it is already engaged in. 9. A type of market that may be substitutable with other brands, a particular firm's product may slightly differ in terms of packaging, design, color and other features. 10. A type of market that exists when there is only one producer or seller of a good or a service which has no close substitute in the market