The poor boy __ the test again; in that case, his mother will be very disappointed.
| A．must have failed | B．might fail | C．could have failed | D．should fail |
The car is environmentally friendly because it uses electricity instead of gas. _____, it is less expensive.
| A．Besides | B．However | C．Instead | D．Therefore |
She showed me a red silk dress _____ online, which cost her only 10 dollars.
| A．to be bought | B．being bought | C．bought | D．having bought |
Having no enough time to practice, the girl wondered whether she _____ pass the driving test.
| A．should | B．could | C．might | D．must |
I recorded the professor’s speech on my cellphone _____ I could listen to it several times later.
| A．in case | B．now that | C．even though | D．so that |
—You seem tired, David.
—Yes. I _____ all day long and can’t wait to go to bed now.
| A．am working | B．had been working |
| C．have been working | D．was working |