题目

切取某动物合成生长激素的基因，用某方法将此基因转移到鲇鱼的受精卵中，从而使鲇鱼比同类个体大了3～4倍，此项研究遵循的原理是（ ）                                                                          A．基因突变DNA→RNA→蛋白质                   B．基因工程DNA→RNA→蛋白质          C．细胞工程      D．基因工程           — I called you yesterday evening, but no one answered.— I ______in my bedroom at that time.A. read        B. was reading     C. am reading