24. What soil(s) is(are) the most fertile? (A) humus only. (B) loam only. (C) silt only (D) both humus and loam

2. Genetically engineered plants (A) are more difficult to engineer than animals. (B) include a transgenic rice plant that can help prevent are more difficult to engineer than animals t vitamin A deficiency. (C) are being rapidly developed, but traditional plant breeding programs are still the only method used to develop new plants. (D) are able to fix nitrogen themselves