Although Igor Ivanovich Sikorsky was not the(1) .... of the helicopter. INVENT The (2)....of his contribution to its development is not in doubt. IMPORTANT (3).... thousands of years ago, the Chinese played with APPEAR (4).... Toys could fly into the air, and even da Vinci drew plans for a helicopter. WOOD However, at that time, it was (5)..... to build a real one. POSSIBLE Century, science become (6).... advanced enough and Sikorsky was the (7)..... TECHNOLOGY SCIENCE who made the successful helicopter a reality. As a child, Sikorsky had been encouraged by his mother, a doctor, and his father, a (8)...., to view science as a series of connected (9)..... PSYCHOLOGY DISCOVER Today, all modem Hali copter are based on his (10).... designs. REVOLUTION

Вот какие формы слов логично вставить в пропуски (с пояснением, почему именно так):

1. inventor
   Фраза: was not the … of the helicopter — после the нужен существительное (тот, кто изобрёл) → inventor.

2. importance
   Фраза: The … of his contribution — нужна сущ. форма от important → importance (важность).

3. Appearing
   Фраза начинается с причастного оборота: …, thousands of years ago, the Chinese played… — нужно причастие “появившись/появляясь” → Appearing.

4. wooden
   Фраза: played with … toys — нужно прилагательное “деревянные” → wooden.

5. impossible
   Фраза: it was … to build a real one — смысл “невозможно” → impossible (от possible с отрицательной приставкой).

6. technologically
   Фраза: become … advanced enough — слово advanced требует наречия (“насколько продвинута?”) → technologically advanced.

7. scientist
   Фраза: Sikorsky was the … who made… — нужен человек/профессия от science → scientist.

8. psychologist
   Фраза: his father, a …, — профессия от psychology → psychologist.

9. discoveries
   Фраза: a series of connected … — множественное число существительного от discover → discoveries.

10. revolutionary
    Фраза: based on his … designs — требуется прилагательное “революционные” → revolutionary.

Итоговый набор ответов:

1. inventor

2. importance

3. Appearing

4. wooden

5. impossible

6. technologically

7. scientist

8. psychologist

9. discoveries

10. revolutionary