20. Generally, members of which flatworm class(es) are nonparasitic? (A) Turbellaria. (B) Trematoda. (C) Cestoda (D) Monogenea

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