Before my father moved off, he told me again and again that I should ________ the rules and regulations of the school.

Li Na ____________ her husband’s significant contribution in her development on the WTA Tour.

If the computer should_____ within the first three years, we would repair it at our expense.

Jack coughed day and night, so the doctor______him to take the medicine three times a day.

There’s no way of knowing why one man makes an important discovery ___ another man, also intelligent, fails.