Page 27 - Science Tour 3 (Workbook)

Choose:

1. Nitrogen represents ……. % of the atmosphere.

(21 – 78 – 1)

2. During photosynthesis, the plant uses ………… .

(oxygen – nitrogen – carbon dioxide)

3. ………… is used to make proteins.

(Oxygen – Nitrogen – Carbon dioxide)

4. Humans and animals use ………… in respiration.

(oxygen – carbon dioxide – nitrogen)

5. Oxygen represent ……. % of the atmosphere.

(21 – 78 – 1)

6. The most abundant gas in the atmosphere is ………… .

(oxygen – nitrogen – carbon dioxide)

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