. As there is less and less coal and oil, scientists are exploring new ways of making use of ______ energy, such as sunlight, wind and water for power and fuel.
| A．primary | B．alternative | C．instant | D．Unique |
They are young, but ____ they made it.
| A．after all | B．in all | C．above all | D．for all |
The teacher’s words left us _______ .
| A．think | B．to think | C．thought | D．thinking |
Would you explain _____?
| A．the meaning to us | B．us the meaning |
| C．us to the meaning | D．the meaning us |
She advised us _____ carefully in her class.
| A．listen | B．listening | C．to listen | D．listened |
Many things were stolen and the theft _________ unreported.
| A．became | B．left | C．got | D．went |