B4

One morning Mr. Sherlock Holmes was sitting in his room in Baker Street. His friend Dr. Watson was standing near the window looking at a walking stick.
(смотря)

LOOK

B5

This stick had been forgotten by a stranger visitor the day before.
(past perfect passive, т.к. одно действие завершилось до другого в прошлом)

FORGET

B6

The words ‘To Dr. Mortimer’ were written on it.
(past simple passive, т.к. действие совершилось в определённое время в прошлом; был написан)

WRITE

B7

Dr. Watson had already been examining it for half an hour but he could not say anything about it.
(can – настоящее время, could – прошедшее время)

NOT CAN

B8

Suddenly Sherlock Holmes said, ‘The owner of this stick has a dog which is larger than a terrier. I have noticed the marks of a dog’s teeth on the stick.’
(past simple, т.к. действие произошло в определённый момент в прошлом)

SAY

B9

‘Probably the dog often carries the stick behind the master.’ he added.
(present simple, т.к. это общее утверждение)

CARRY

B10

‘I wander why this man wanted to visit us,’ asked Dr. Watson.

‘Well, we soon will know,’ answered Sherlock Holmes.  I can hear the bell ringing.’
(future, буду знать)

KNOW