设NA为阿伏伽德罗常数的值，下列叙述正确的是（ ）
A：丙烯分子有7个σ键，1个π键
B：由2H和18O所组成的水11g，其中所含的中子数为4NA
C：0.1mol SiO2晶体中所含有的硅氧键数目为0.2NA
D：在反应KIO3+6HI=KI+3I2+3H2O中，每生成3mol I2转移的电子数为5NA个
Bob is an English boy. His eyes are blue. Li Ming is a tall boy. His eyes are black. They are good friends. Bob's hair is yellow and Li Ming's hair is black. Li Ming's mom is a Chinese teacher. Bob's mom is an English teacher.她和李明的妈妈在同一个学校。Bob's dad is a doctor(医生). Bob and his dad look different. He looks like his mom. Bob's family are new in China. Li Ming's dad and mom help them(他们). They like their English friends.
End of Term Report
Student's name
Zhang Xing
Subject
English
Teacher
Mr. Dickens
At the beginning of this term
He found that studying English was very ____
In writing
His ____is better.
In speaking
He can have English ____with his friends and with me.
He can answer my questions in English____.
Next term
If he ____like this, he will do much better.
下列选项能体现法律最主要特征的是（ ）
