II. Complete these sentences by using “It+be+Adj+ to V-infi...”. (Hoàn thành các câu sau sử dụng các từ cho sẵn và cấu trúc It + be + adj + to V ...) 1. It's (normal/ feel) ........................... tired after a long trip. 2. It's (difficult/ play) ..................... the piano well. 3. It's (impossible/ complete) ....................... this exercise in 24 hours. 4. They were (happy/ see) ...............................you after 3 years . 5. Mary is ...........................(angry/ hear) that she failed the exam. 6. It's not (easy/ learn) ............................... Japanese. 7. It's (difficult/ explain) ....................... some grammatical rules. 8. It was (important/ eat) .......................... clean and healthy food. 9. It's (dangerous/ go) ......................... out after midnight. 10. We are ............................(delighted/ hear) that you are well.