A：聚丙烯的结构简式为：
B：电石的化学式为：CaSiO3
C：热稳定性：H2S＞HF
D：NH3的结构式为
It is usually warm in my hometown in March, but it ______ be rather cold sometimes.
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.
