составить 5 предложений этими словами make a discovery, date back, do researh, spare, dig, stone tools ,artefacts

1. The scientists made a great discovery in the sphere of cosmos.

2. The date back of credit was agreed in the contract.

3. We must do research according to this program.

4. Have you the spare keys?

5. We dig our kitchen-garden in autumn.

6. Have you ever seen the stone tools?

7. The artefacts are the mistaken knowledge.