Answer:
new moon and full moon
Explanation:
Tides occur due to gravitational force of the sun and the moon. During New moon and Full moon, the Sun and the Moon are aligned in a straight line. This alignment leads to strong effect of gravity on tides and highest high tides and lowest low tides occur. These tides are referred as spring tides.
Neap tides occur when the sun and the moon are aligned at right angles. Effect of gravity is minimum and low tidal range is observed.
