If certain species _____ extinct, an expert in New York, says there would be enough resources to reintroduced them in the future.
| A．had become | B．would become |
| C．are becoming | D．should become |
It has been five days since the three boys disappeared in the flood, so the chances are slight _____ they will be found alive.
| A．how | B．that | C．whether | D．when |
When I was young, I always went to the cinema on weekends and _____ sit there happily for hours.
| A．should | B．could | C．would | D．must |
---The president has expressed you shall be promoted after you complete the challenging project.
---But I am afraid his promise is nothing _____ he has carried it out.
| A．after | B．until | C．once | D．since |
A situation often appears where we know what a word means and how to read it but it has _____ our minds when we want to write it down.
| A．escaped | B．crossed |
| C．occupied | D．eased |