A:闭合K1,有电子从枕型导体流向大地
B:闭合K2,有电子从枕型导体流向大地
C:闭合K1,有电子从大地流向枕型导体
D:闭合K2,没有电子通过K2
根据材料内容,选择正确答案。
There are 50 students in Class 8. Now they are doing a survey about how they spend their pocket money. Some spend it on books, and others spend it on visiting. What about you? Please read the form and answer the questions.
10%
55%
12%
13%
Buy some CDs and computer games.
Buy some snacks and drinks.
Buy some books in the bookshop.
Save it up and spend it traveling on holiday.
Buy some gifts for friends.
下列自然资源中属于非可再生资源的组合,正确的是( )
①煤 ②水资源 ③土地资源 ④天然气
小王的手指不慎划破出血,血液中与伤口止血和避免发炎有关的成分分别是( )