Поставить глаголы в правильную форму. 12. He _____ (not/ hear) the

Поставить глаголы в правильную форму. 12. He _____ (not/ hear) the thunder during the storm last night because he _____ (sleep).13. We hope that scientists ______ (find) solutions to our most urgent problems.14. By next decade people _______ (create) more efficient purification equipment. 15. What geologists ______(study)?16. There isnt a cloud in the sky. It ______ (be) a lovely day.17. This time last year I ______ (swim) in the Black Sea.18. They ____ (work) at a chemical laboratory now.19. In 1974, scientists _______ (not / predict) an earthquake in China.20. They ______ (carry out) an experiment from ten till twelve oclock in the morning.21. He _____ (solve) this problem by 10 oclock yesterday.