连接曲线的三要素是道岔号数、股道线间距和()。
A.股道长度
B.钢轨类型
C.连接曲线长
D.连接曲线半径
参考答案:D
______ tired, after a hard work, she fell into bed and went straight to sleep.
A.Felt
B.Feeling
C.Being felt
D.To feel
结合实际说明行为改变的几种方法。