Question

give reasons (i) it is difficult to set curd in winter (ii) your mother dries the pieces of un ripe mango (iii) food stuff is kept in the refrigerator to prevent their spoilage (iv) surgical instruments are boiled in water before using them again for an operation (v) 'gobar gas ' is of great utility for people living in villages (vi) leguminious plants are benefitted by having rhizobium bacteria in their roots

Answer 1

It is difficult to make curd in winter because curd forms due the lactobacillus bacteria which grows faster in the high temperature.
Food is kept in refrigerator because bacteria does no grow in low temp.
The plants are by benefit because it helps in nitrogen fixation.
The inst uments are dipped in hot water because it kills the bacteria's.