句子加工厂

静寂笼罩着这座水上城市。 

1．改成“被”字句：                                                                                                          

2．改成设问句：                                                                                                                 

3．改成双重否定句：                                                                                                         

渗透性利尿是直接由于

A．血浆晶体渗透压升高

B．远曲小管和集合管内小管液溶质浓度升高

C．远曲小管和集合管对Na⁺的通透性降低

D．远曲小管和集合管对水的通透性降低