Every possible means_____ been tried,and we find only______ this means can we do it well.
– Do you know William failed the exam, Jenny? -- _____? As far as I know, he is always working hard.
When you communicate with people, it is not unusual to find yourself in a situation ____ you have to politely decline an offer.
Not until Betty got to the airport _____ she had lost her tickets.
____ has been proved again and again that ____ is said in the ads greatly affects people’s impression of the products.
_____ no spare parts, the equipment could not be repaired at once.