### Instruction:

Extract the cause and effect entities from the following sentence:
Arduino features add-on modules called “shields”, which allow to add preassembled circuits to the main board to control motors, add Ethernet, Bluetooth, ZigBee, etc

### Assistant:

KEYWORD: which allow
VARIABLE: preassembled circuits
CONDITION: to the main board to control motors, add Ethernet, Bluetooth, ZigBee,
CAUSE_1: Arduino features add-on modules called “shields”
NOT_RELEVANT: etc
EFFECT_1: to add preassembled circuits to the main board to control motors, add Ethernet, Bluetooth, ZigBee

