2786: Which feature of some, species of blue-green algae helps promote them as bio-fertilizers?
(a) They convert atmospheric methane into ammonia which the crop plants can absorb readily
(b) The induce the crop plants to produce the enzymes which help convert atmospheric nitrogen to nitrates
(c) They have the mechanism to convert atmospheric nitrogen into a form that crop can absorb readily
(d) The induce the roots of the crop plants to absorb the soil nitrates in larger quantities
2787: Which one of the following pairs of countries fought wars over a region called Ogaden?
(a) Eritrea and Sudan
(b) Ethiopia and Sudan
(c) Ethiopia and Somalia
(d) Kenya and Somalia
2788: Sound waves travel at 300 m/s. Sound produced at a point is heard by a person after 5 seconds while the same sound is heard by another person after 6 seconds. What could be the maximum and minimum distances between the two persons?
(a) 1.8 km, 0.15 km
(b) 2.2 km, 0.20 km
(c) 2.8 km, 0.25 km
(d) 3.3 km 0.3 km
2789: Which of the following is the chief characteristic of 'mixed farming'?
(a) Cultivation of both cash crops and food crops
(b) Cultivation of two or more crops in the same field
(c) Rearing of animals and cultivation of crops together
(d) None of the above
2790: The partition of Bengal was undertaken with the view of:
(a) Suppressing the revolt arisen
(b) Satisfying the Hindus and the Muslims
(c) Meeting the demand by the Hindus and the Muslims for a separate State
(d) Dividing the Hindus of the West Bengal and increasing Hindu-Muslim tensions