1 – A, 2 – B, 3 – C, 4 – D, 5 – E

5. Khí khổng e. Bảo vệ.

A. 1 – a, 2 – b, 3 – c, 4 – d, 5 – e. B. 1 – a, 2 – d, 3 – e, 4 – b, 5 –c

C. 1 – b, 2 – d, 3 – e, 4 – c, 5 – a. D. 1 – c, 2 – d, 3 – e, 4 – b, 5 – a.