Complete the text with suitable prepositions. Cottage industry is very important (a) ____ self-employment (b) ____ a country. It opens the doorway (c) ____self-employment (d) ____ grass-roots level (e) ____ Bangladesh. Attention (f) ____ this industry should be paid (g) ____ the progress (h) ____ a country. (i) ____ the past, a lot of Bangladeshis were engaged (j) ____ cottage industry.