The pump has a constant stroke and the amount of fuel delivered is regulated by rotating _____ which has a specially arranged helical groove cut into it.
【简答题】听下面一段材料,回答第1至4题. 1. What was Miss Richards? A. A PE teacher. B. A music teacher. C. A science teacher. 2. What question did Miss Richards ask her students? A. What was water? B. What colour was water?...