detective; to do detective work

to explore; to search out; to scout; to visit; to stretch forward

secret agent; detective; covert investigator

to sound out; to probe; to feel out; to try out

to make discreet inquiries; to scout out

to pry into or spy on; to snoop; to peep; to poke one's nose into; to peer; to get a glimpse of

master sleuth; lit. miraculous detective; cf Sherlock Holmes 福爾摩斯|福尔摩斯[Fu2 er3 mo2 si1] or Di Renjie 狄仁傑|狄仁杰[Di2 Ren2 jie2]

to conduct exploratory drilling

to pry into; to spy on; to probe into

to conduct an exploratory foray into (an area of study, a market etc); a preliminary study

to explore; to survey; to prospect (for oil etc); prospecting

detective (in former times)

to sniff (in order to find sth)

inside informer; mole; plant

enemy spy

secret agent; detective

to check; to investigate; to probe (into)