poplars
                                                                
                
                
                    
                                                                                                                        poplars 双语例句
                
                
                    
But steven strauss , a forest biologist at oregon state university , says that because of the great genetic variation in willows and poplars , genetic modification may not be necessary .    但是俄勒冈州立大学(oregonstateuniversity)的史提芬斯特劳斯(stevenstrauss)指出,鉴于柳树和杨树的种类繁多,它们不一定需要进行基因改造。