—Did you look up the time of trains to Shanghai?
—Yes, the early train is ________ to leave at 5:00 am.
| A．likely | B．about | C．possible | D．due |
Before I left home, my mother taught me ________some simple dishes, such as noodles and garlic with vegetables.
| A．what cooking | B．how cooking | C．what to cook | D．how to cook |
In order to find the missing boy, the young couple all they can over the past twenty-four hours.
| A．do | B．did | C．have been doing | D．had done |
The young manager is well known for his problem-solving skills, ________ is important for a successful leader.
| A．it | B．that | C．what | D．which |
Not until he had left his friend _______ how important friendship was for him.
| A．did he realize | B．he realized | C．had he realized | D．he had realized |
My father worked day and night. Otherwise, there ________ no one to support the family.
| A．would be | B．must be | C．would have been | D．must have been |