How many characters appear in this drama?

A. 7
B. 8
C. 9

Did the two wrong men take the right paper?

A. Yes
B. No
C. Not mentioned

Why didn’t the professor’s daughter stay with her father?

A. Freda is in hospital.
B. Miss Green isin hospital
C. The professor isin hospital.

How long had the professor read the paper when two wrong men arrived?

A. One hour and a half
B. One hour
C. Half an hour

How didthe professor know that these two people are not the right people?

A. The two men arrived in the professor’s room earlier.
B. The two men claimed that they knew the professor’s invention.
C. The two men did not show their cards to the professor.

The professor finally decided ________ would send the paper to London?

A. His secretary
B. The professor himself
C. Inspector Hadley

Please put the following sentences in the right order according to the development of the story.