### Instruction:

Extract the cause and effect entities from the following sentence:
To measure the shear from the galaxy ellipticities a tight control is imposed on possible instrumental effects and will lead to the variance of the shear systematic errors to be less than 10–7

### Assistant:

VARIABLE: the shear from the galaxy ellipticities
CONDITION: To measure
KEYWORD: will lead to
CAUSE_1: a tight control is imposed on possible instrumental effects
EFFECT_2: the variance of the shear systematic errors to be less than 10–7
EFFECT_1: To measure the shear from the galaxy ellipticities
AND: and

