猪饲料中泥沙含量不应超过()。
A、0.5%-1%
B、1%-1.5%
C、1%-2%
D、2%-2.5%
参考答案:C
. ______ the question made her teacher angry and upset.
A.Jenny refuses to answer
B.Jenny refusing to answer
C.Jenny’s refusing to answer
D.Jenny’s refusing answering
曲线轨道加强的措施有()。
A.重型钢轨
B.增加轨道和道床的宽度
C.安设轨距杆或轨撑
D.铺设护轨
E.轻型钢轨