________ these experiments were successfully completed would we think of going into humans.
| A．If only | B．Only if | C．So that | D．Even if |
You have nothing to _______ by refusing to listen to our advice.
| A．grasp | B．gain | C．earn | D．catch |
The guitar ________ Dave composed our first hit is in a music museum.
| A．in which | B．to which |
| C．with which | D．by which |
--- John, I didn’t ask for the dictionary. Why ______ on my desk ?
--- Oh, I put it there just now in case you needed while writing your composition.
| A．had it landed | B．does it land |
| C．will it land | D．has it landed |
There are times when a play became highly successful, even though most of the critics panned(抨击) it without _________.
| A．intention | B．regret |
| C．relief | D．mercy |
Many computer games _______ a lot of violence and do teenagers a lot of harm.
| A．contain | B．cover | C．include | D．act |