In the paper bridge competition in our school, when we used two pieces of paper and glue with A 1 as the bridge, the span was 50 cm, the width was 10CM, and the mass was less than 150 g, and then we carried a load in the middle. Our group took 5 1.5 kg and won the championship.

Although you only have a piece of A4 paper, the span is only 15CM, the width is 5CM, and the load is only 600g, which is completely possible.

Roll two paper poles at 1, control the size, the length is slightly longer than 15, that is, the span, and control the paper consumption, and don't use too much.

Fold two pieces of paper tape, not too thick, because the paper tape has strong stretching ability, and its length is about 1/3 longer than the paper rod.

3. Connect two paper poles with short cross bars at regular intervals (just add four, two in the middle and one on each side), so that the width is not less than 5.

4 Connect the two sides of the paper tape with the two sides of the paper rod respectively (at this time, only the paper tape will droop because it becomes longer), then roll up four shorter paper rods and support the paper rods symmetrically on the paper tape. Finally, an isosceles trapezoid with a long top and a short bottom is formed. Four short paper poles support the middle of the upper paper pole from the lower vertex of the trapezoid.

Finally, the workmanship should be fine. If it's done well, it should be 5 kilograms, no problem. If you want to raise the deck, you can add four columns at both ends of the bridge. As a dock, our competition is unlimited.

Wish you success!