无砟道床分为CRTSⅠ型板式、CRTSⅡ型板式、双块式以及道岔区（）和板式无砟道床等。
参考答案：轨枕埋入式
The monument was built in honor of the explorer who was believed＿＿the big river.
A．to have discovered
B．to have been discovered
C．to be discovered
D．having been discovered
腹部肿瘤腹腔镜分期的突出优点为
A．诊断治疗一体化B．可直观直接地获取诊断依据C．创伤小、痛苦轻D．可避免不必要的开腹E．以上均正确
