英语选择题I called at ___________ three times the day before yest

英语选择题
I called at ___________ three times the day before yesterday.
A. my teacher B. my teachers
C. my teacher‘s D. the teacher of mine
It’s _________ as the one we did last month.
A. as dangerous a job
B. as a dangerous job
C. so dangerous a job
D. such dangerous job
You should take the medicine after you read the __________.
A. introduction B. words
C. instructions D. suggestions
请重点讲解下第二题
instruction 不就是说明书的意思吗 为什么还加s