______ the students found the soldier’s idea interesting, the system was too difficult to be of practical use.
| A．While | B．Unless | C．As soon as | D．Even if |
He hesitated for a moment before kicking the ball, otherwise he ______ a goal.
| A．had scored | B．scored | C．would score | D．would have scored |
Mr. Bush is on time for everything. How ____ it be that he was late for the opening ceremony ?
| A．can | B．should | C．may | D．must |
You can’t imagine that a well –behaved gentleman ______ be so rude to a lady.
| A．might | B．need | C．should | D．would |
— Write to me when you get home.
— __________.
| A．I must | B．I should | C．I will | D．I can |
I was really anxious about you. You _______ home without a word.
| A．mustn’t leave | B．shouldn’t have left | C．couldn’t have left | D．needn’t leave |