题目

你能想象一棵苹果树上长出三种不同口味的苹果吗？运用生物技术就可以做到，这种技术是（    ） A．嫁接             B．扦插        C．异花传粉     D．组织培养 答案：A 一Why did Miss Wang look so worried when we saw her? —Because she wondered________． A．where did the other students go B．when would the policeman come C．what her students have done during the trip D．if her students had survived the earthquake