To watch (someone) secretly
SPY ON
A person specially trained to design and build machines, structures, and other things, including bridges, roads, vehicles, and buildings
ENGINEER
An expert in science, esp. one of the physical or natural sciences
SCIENTIST
Any basic discrete device or physical entity in an electronic system
ELECTRONIC PARTS
to (cause something to) grow or change into a more advanced, larger, or stronger form
DEVELOP
Say something in reply
RESPOND
A machine, usually with wheels and an engine, used for transporting people or goods, especially on land.
VEHICLE
To get and keep things of one type such as stamps or coins as a hobby
COLLECT (verb)
The necessary items for a particular purpose
EQUIPMENT
to make (something) better
IMPROVE
A member of any of the races of Homo sapiens; person; man, woman, or child
HUMAN BEING
Being what it appears to be and not false
REAL
To cause (a person or animal) to do what you want
CONTROL
A device, machine, or piece of equipment, especially an electrical one that is used in the house, such as a cooker or washing machine
APPLIANCE
Very unusual or remarkable
EXTRAORDINARY