Lesson 19-20 practice your english

Some of the sentences given below have errors in them. The error is in the underlined word. Correct it.

• Plastic normally take over 1000 years to decompose. Now a 16-year-old Canadian boy has found a way to make plastic decomposing within three months. In his experiment Daniel Burd has mixed landfill dirt with yeast and tap water. He then adds ground plastic and let it stew. Plastic did decompose much faster than it normally do. Daniel said that the process can be carried out easy on an industrial scale: all what is needed is a fermenter, a growth medium and plastic. The young student’s accomplishment helps him win the top prize at the Canada-Wide Science fair in Ottawa.