=240÷6,

=40 (mm);

A: The average monthly precipitation in the first half of 2006 was 40 mm. 。

(3)(60-50)÷50,

= 10÷50,

=20%;

A: The precipitation in June is 20% more than that in April.

(4) Question: What percentage is the precipitation in February more than 1 month?

(30-20)÷20,

= 10÷20,

=50%;

A: The precipitation in February is 50% more than that in 1 month.

So the answer is: 40, 20.