Which of these microorganisms is useful?

Which of these microorganisms is useful? WHICH OF THESE DO YOUTHINK IS THESECONDMOST USEFUL INVENTION Which of these do you think is the most useful invention?中do 请帮忙填空：Which of these do you think is ---useful invention? Which of these do you think is ____ useful invention? [  Which of these statements is always true? Which of these is true 怎么翻译 which one of these is the national fiag of france? Which of these is an example of climate.怎么翻译? Which of these animals_______highest? Which of these sentences is TRUE?怎么翻译 Which of these is true 翻译中文后的意思