引起雏鸡脑病变的机制是()(P325-12)
A、氧化磷酸化过程障碍
B、抗氧化功能障碍
C、突触传递障碍
D、神经递质生成障碍
E、离子通道障碍
参考答案:B
The young graduate ______ his vegetable farm so successfully that soon he became No 1 vegetable
producer in the area. [ ]
A. made
B. performed
C. worked
D. discovered
与尺寸公差带相比,形位公差带是限制实际要素变动区域,除有一定的大小,还有一定的()。
A.形状
B.方向
C.形状、方向和位置
D.位置