Reading materials for the Winter Olympics and traditional festivals

A: 10 The Winter Olympics was held in 1968.

(2) Because 6÷60= 1 10,

So 4 minutes and 06 seconds =4 1 10 minutes;

(3)4 minutes 06 seconds =246 seconds,

3000÷246≈ 12.2 (m),

Answer: It glides about12.2m per second.

(4)3×( 12÷2) 2 ×35÷2,

=3×36×35÷2,

= 1890 (m3)，

Answer: It is necessary to dig out 1890 cubic meters of soil.

(5)3× 12×35÷2=630 (square meters),

We need to lay an extra 630 square meters of roller skating ground.

So the answer is:1968; 4 1 10 .