bar-headsBNC²³⁶²¹³⁺¹ 例句 “ Geese are a relatively old group of birds, and it's possible that when bar-heads first evolved as a species, the mountains weren't nearly as high as they are today, ” Hawkes said. 霍克斯说，“雁是一种相对古老的鸟类。有可能在斑头雁进化成一个独立的物种之时，这些山并非如今日这般高大。” yousoon