1. ............ is a small device, especially an electrode, used for measuring, testing, or obtaining information.

Probe

Prop

Probity

Proobe

2. The investigators ............ Nathan for hours, trying to find out what he knew.

probes

probing

probeid

probed

3. ............ isn't the synonym of probe.

Examination

Exploration

Investigation

Procedural

4. The doctor inserted a ............ into the patient's left nostril to investigate the cause of the blockage.

probe

probed

prop

propy

5. What do you probe ............ without knowing what we want ?

for

on

of

at