1 detective

2 to do detective work

1 to explore

2 to search out

3 to scout

4 to visit

5 to stretch forward

1 to explore

2 to probe

1 to observe

2 to watch

3 to survey

4 to examine

5 observation

6 view

7 perspective

8 classifier: 个 gè

1 police

2 police officer

3 classifier: 个 gè

1 to examine tiny clues to know general trends (idiom)

2 to deduce the whole story from small traces

1 to weigh up sb's words and observe their facial expression (idiom)

2 to discern what sb thinks from his body language

1 to poke one's head in and pry (idiom); to spy

2 nosy

1 to feel in one's pocket and take sth (idiom); as easy as pie

2 in the bag

1 to stick one's head out and look around (idiom)