Some weedkillers stop the plant from photosynthesising. These are often applied to the soil where the weeds are growing. Explain how the weedkiller reaches its site of action in the leaves.​

is a Polish education technology company based in Kraków, Poland, with headquarters in New York City. It provides a peer-to-peer learning platform for students, parents, and teachers to ask and answer homework questions. The platform has elements of gamification in the form of motivational points and ranks. It encourages users to engage in the online community by answering other users’ questions. As of November 2020, reported having 350 million monthly users, making it the world's most popular education app.[5]Initially called Zadane.pl, the company was founded in 2009 in Poland by Michał Borkowski (current chief executive officer), Tomasz Kraus and Łukasz Haluch. The first million unique users monthly was achieved within 6 months after the release.[6]

In January 2011, the company founded the first international project dedicated to Russian language speakers.[7] Several other versions in multiple languages for the following markets included Turkey Latin America and Spain and Brazil

In December 2013, seven new language versions of were released, including English Indonesian Indian Filipino Romanian (.ro) and Italian (.it) sites. was initially funded by the co-founders, but then raised funds from Point Nine Capital.[9][10]

In October 2014, the company announced that it had raised another round of funding from