The driver could have survived but he _____ the seat belt. [ ]

A. had been wearing

B. hadn't worn

C. wasn't wearing

D. didn't wear

受精后，花的各个部分会发生明显的变化。一般情况下，____、____、____和雌蕊的____、____都逐渐凋落，只有子房继续发育。子房壁发育成________，胚珠发育成________，其中________发育成种子的胚，________发育成胚乳；整个________发育成。