IDNStudy.com, ang iyong mapagkukunan ng mabilis at pangkomunidad na mga sagot. Magtanong at makakuha ng detalyadong sagot mula sa aming komunidad ng mga eksperto na may kaalaman.

David wanted to measure how fast different insects can crawl. He must have a ruler to help him find the speed. What other tool does he need to use?