20.在下面一段文字横线处补写恰当的语句,使整段文字语意完整连贯,内容贴切,逻辑严密,每处不超过12字。(5分) 臭氧是个亦正亦邪的角色,是正还是邪, ① :在距地面10-50千米的高空,臭氧是地球的卫士,能吸收紫外线、保护地球上的生物;到了距地面100米左右的近地面层, ② ,引发头痛、胸闷甚至肺气肿等症状。除了对人体健康的伤害,臭氧污染 ③ 。臭氧浓度达到50ppb时,全国冬小麦就会减产413.2万吨;而英国每年因为臭氧污染
-How are you getting on with the book?
-I had wanted to finish reading it by noon, but it didn't ________ as planned.
[ ]
A.
find out
B.
work out
C.
let out
D.
cut out