Though Tom knew nothing about business, he succeeded ________ other more well-informed managers failed.
| A．what | B．how | C．if | D．where |
The machine has begun to ___.
| A．have its work | B．take its work | C．do its work | D．show its work |
I regret ___ harder in the past two years.
| A．not having studied | B．having studied | C．having not studied | D．not being studied |
Had your father seen the doctor earlier, he ___.
| A．would have died | B．would not have died | C．would not die | D．has not died |
Tom’s uncle must be an engineer, ___?
| A．mustn’t he | B．can’t he | C．isn’t he | D．needn’t he |
He ___ on the grass, looking at the clouds in the sky.
| A．is laying | B．is lying | C．has laid | D．has lied |