clozes

Mr Tam has been afflicted with an annoying problem recently. For the past two months , he has been (suffering) from severe back pain. Last week, he went to the hospital for a (physical/medical) checkup. Apart from an X-ray examination, he was given medicine to (relieve) his pain.
Mr Tam isn't an old man. He is (about) forty something . He (runs/owns) a small company himself. Most of the time, he does paper (work) at the office. A few months ago, one of his assistants (left) the company and Mr Tam didn't have (anyone) to help him. Sometimes, he even (needed) to do heavy manual work. Now Mr Tam (is) hard to think back to what had (happened) before his backache. About two months ago, he had to move (something) heavy. It was only a few boxes.

~ suffering (intr. v) - no passive voice
~ owns a company and runs the business
~ "Now" switches the tense back to "present"
~ happened
~ something

2014-08-28 09:13:12 補充：
Correction:
"hard' should be an adverb, so we need an action verb instead of a linking verb.

Now Mr. Tam "is trying" hard to think back to what had happened before his backahce.

If you agree with something in principle, you don't agree in general terms to the idea of the principal 2nd in charge.(1)suffering (passive), (2)medical/physical, (3)relieve, (4)about, (5)owns, (6)work, (7)left, (8)anyone, (9)needs, (10)was, (11)happened, (12)something.

he has been (suffering) from severe back pain.
He (runs) a small company himself.
Sometimes, he even (needs) to do heavy manual work.
Now Mr Tam (is trying) hard to think back to what had (happened) before his backache.
About two months ago, he had to move (something) heavy.