单选题 I had to work extremely carefully, for I didn't know how long ______ to get used to the new tool.
A. it would take me B. it would spend me
C. would it pay me D. would it cost me

【正确答案】 A
【答案解析】[解析] 本题考查It takes sb. some time to do sth.的句型和陈述语序。