1. I ..........hard, so I felt very tired.

a) had worked b) have worked c) had been working

2. I........ my money into real estate.

a) invested b) have invested c) invest

3. We already........the goods when your telegram arrived.

a) have shipped b) had shipped c) shipped

4. The invoice ........ by the end of the week so we sent them a strong reminder.

a) had arrived b) hasn't arrived c) hadn't arrived

5. I ..........nothing in the Internet this month.

a) have bought b) didn't buy c) haven't bought

6. This strategy seems to be good. Sales of our products......... for

some time.

a) have increased b) have been increasing c) had been increasing

1 2 3 4 5 6

1. I ..........hard, so I felt very tired.

a) had worked  - if you want to emphasise that the job had been finished before you felt tired

c) had been working  - if you want to say that performing some work made you tired

2. I........ my money into real estate.

b) have invested - if you mean that it's going give you profits

a) invested - if it happened some time ago and there's no connections to present situations

3. We already........the goods when your telegram arrived.

 b) had shipped  

4. The invoice ........ by the end of the week so we sent them a strong reminder.

 c) hadn't arrived

5. I ..........nothing on the Internet this month.

a) have bought  

6. This strategy seems to be good. Sales of our products......... for some time.

b) have been increasing