The novel written by the author________ well，but five years ago no one could have imagined how great a role he ________in the literary world.[ ]

A．sells；was to play  

B．selling；was playing

C．sold；had played  

D．sell；is playing

上人屋面预制板块保护层，块体材料应按楼地面工程的质量要求选用，结合层水泥砂浆应选用______水泥砂浆。

A．1:1

B．1:2

C．1:3

D．1:4