填入下面横线处的句子，与上文衔接最恰当的一句是 （ ）据统计，迄今为止，大约有500人成功地登上了珠穆朗玛峰顶，但也大约有500人却在攀登过程中献出了宝贵的生命。这个统计数字不折不扣地表明：__________

What does Old Walter usually do in hisretirement—- These days he is ______ memories of village lifefor his new book

There are so many books. Would you please ask some students _______ me ______ them to the classroom — Ok.

Ann is in hospital.— Oh ,really? I ______ knowI ______ go and visit her.[ ]

Sam ___________a newspaper when the bus stopped rapidly.