单项选择题
If（）, visit a local law enforcement office and ask their opinion.
A.in doubt B.in case C.in condition D.in detail
单项选择题 Thoroughly conduct a background check on the company, （）as many phone calls and Internet searches as you can.
单项选择题 Take the time to（）the validity of an offer.
单项选择题 All offers（）require payment or private information before giving an award are bogus.
