题目

根据等电子原理推测下列微粒构型不是正四面体的是（    ）A.SiCl4            B.           C.               D. 答案：解析：等电子原理是指电子总数或价电子总数相同，且原子总数相同的分子或离子具有相同的结构特征。答案：DWe now think of chocolate as sweet, but once it was bitter. We think of it as a candy, but once it was a medicine. Today, chocolate can be a hot drink, a frozen dessert, or just a snack. Sometimes it is an ingredient in the main course of a meal. Mexicans make a hot chocolate sauce called mole and pour it over chicken. The Mexicans also eat chocolate with spices like chili peppers. Chocolate is a product of the tropical cacao tree. The beans taste so bitter that even the monkeys say “Ugh!” and run away. Workers must first dry and then roast the beans. This removes the bitter taste. The word “chocolate” comes from a Mayan word. The Mayas were an ancient people who once lived in Mexico. They valued the cacao tree. Some used the beans for money, while others crushed them to make a drink. When the Spaniards came to Mexico in the sixteenth century, they started drinking cacao too. Because the drink was strong and bitter, they thought it was a medicine. No one had the idea of adding sugar. The Spaniards took some beans back to Europe and opened cafes. Wealthy people drank cacao and said it was good for the digestion.    In the 1800s, the owner of a chocolate factory in England discovered that sugar removed the bitter taste of cacao. It quickly became a cheap and popular drink. Soon afterwards, a factory made the first solid block of sweetened chocolate. Later on, another factory mixed milk and chocolate together. People liked the taste of milk chocolate even better.    Besides the chocolate candy bar, one of the most popular American snacks is the chocolate chip cookie. Favorite desserts are chocolate cream pie and of course an ice cream sundae with hot fudge sauce. It was ______that discovered sugar could remove the bitter taste of cacao. A. the workers in the chocolate factory     B. the Spaniards  C. the people in England                D. the owner of a chocolate factory. According to the passage which of the following statements is TRUE? A. Nobody had the idea of adding sugar until the sixteenth century. B. The word “chocolate” comes from a Mexican word. C. The beans taste so bitter that even the monkeys like them.   D. Workers must dry and roast the beans to remove the bitter taste. It can be inferred from the passage that___________.    A. chocolate can be a hot drink, a frozen dessert, or a candy bar  B. Mexicans like chocolate very much        C. chocolate is a product of the cacao tree D. people liked the taste of chocolate mixed with milk Which is the right time order of the events regarding chocolate?    a. Chocolate became a cheap and popular drink in England.    b. A factory made the first solid block of sweetened chocolate.    c. The Spaniards started drinking cacao.    d. It was found that sugar removed the bitter taste of cacao.    e. A factory mixed milk and chocolate together.    A. a-b-c-d-e    B. c-d-e-b-a            C. c-d-a-b-e            D. c-d-b-e-a