根据短文内容及提示完成短文。

     1._______ middle school, Wang Wei and I have dreamed about 2._______ (have) a great bike trip. It was

Wang Wei 3._______ first had the idea 4._______ (cycle) along the entire Mekong River 5._______ where it

begins to where it ends. My sister doesn't care 6._______ details, because she doesn't know the best way of

7._______ (get) to places. When I told her the difficulties we would come 8._______ during the journey, she

gave me a 9._______ (determine) look-the kind that said she would not change her mind. I know 10._______

she has made up her mind, nothing can change it. Finally, I had to give in.

关于抵押权与期间的关系，下列表述是错误的：（）。

A、抵押权是物权，不受诉讼时效的限制。

B、抵押权是物权，物权是永久权。

C、抵押权受合理期限的限制。

D、抵押权人应当在主债权诉讼时效期间行使抵押权；未行使的，人民法院不予保护。