| 1 | Well we know stock prices are never negative. | |
| 2 | We will never have a case where ionization energy is negative. | |
| 3 | It is a conservative system so all the energies are negative. | |
| 4 | Well it could go twenty basis points lower but interest rates can never be negative. | |
| 5 | Tudou has a history of negative cash flow, and intends to keep increasing its costs as it expands. |