在底面周长是62.8厘米的圆柱形玻璃钢中放一个铁块,睡眠离钢底8厘米,取出铁块后睡眠下降到6厘米,体

摄食羊肉可以减少心血管系统疾病的危害的根据是()。

A.羊肉含胆固醇少

B.羊肉蛋白质含量高

C.羊肉的氨基酸种类齐全

D.羊肉肉质鲜美

试述如何提高绵羊人工授精的受胎率？

毛干(名词解释)

内蒙古细毛羊是以苏联美利奴羊，高加索羊，新疆细毛羊和德国美利奴羊与当地蒙古羊母羊，采用育成杂交方法育成。()

What did the Dodds do when they went away last summer？

A．They hired someone to stay in their home.

B．They left their pets with neighbors.

C．They rented their house to a student.

D．They asked their gardener to watch their house.

请帮忙给出正确答案和分析，谢谢！