题目

As parents we like to make sure that our children are eating well and getting all the nutrients they need. Children need two to three kinds of vegetables every day. A simple way to get our children to eat vegetables is by eating them ourselves. Following our example, they may start eating vegetables themselves. Don’t say things like, “If you eat your vegetables, you can have dessert.” The methods work for a little while but can possibly lead them to hate vegetables more. Give your children new varieties of foods which will help them develop a taste for trying new things. Sometime已知化合物B3N3H6(硼氮苯)与C6H6(苯)的分子结构相似，如下所示： 则硼氮苯的二氯取代物B3N3H4Cl2的同分异构体的数目为 [　　] A．2B．3 C．4D．6