问题 填空题

(4分)下图为某化学反应的微观过程,其中“”和“”表示两种不同原子。

(1)从图中你能获得的信息是 ________;虚线框内应填的微观图示是________                                                              (选填A、B、C、D),你选择的依据是         

(2)该反应属于          (填基本反应类型)。

答案

(1)在化学变化中分子可以再分(或化学反应前后,元素的种类不变;原子在化学变化中不能再分;化学反应的实质是分子分成原子,原子重新组合等)   D  质量守恒定律 

(2)分解反应

题目分析:化学反应的本质就是分子分解成原子,原子再重新组合成分子的过程,在此过程中,分子种类改变,但原子的种类、数目、质量都不改变,因而,化学反应遵循质量守恒定律。而由一种物质发生反应,生成多种物质的反应属于分解反应类型。

点评:本题属于综合类题目,考查的都是初中化学中的重要知识点,要掌握好。

阅读理解

Education cuts(削减) have become routine (惯常的) over the past few years, which has made it difficult for students to learn. The results of a survey of 1,850 Los Angeles County high school students show just how much the cuts are affecting students.

Because of teacher layoffs (解雇), class sizes at some high schools have risen to 50 students — even in math and English classes. Some 37 percent of students report that they sometimes don’t have a desk to sit at. Sixty-seven percent say crowded classrooms make them feel the teachers don’t have enough time to teach, and 30 percent say they’ve not been able to join in a program because it’s no longer offered at their school.

At a time when technology is an important skill, 52 percent of students say there aren’t enough computers. Or they’re often broken, and there’s no one to fix them. Fifty-one percent say they’ve had to share textbooks with a classmate because there aren’t enough copies to go around. Fifty-seven percent say they’ve had to copy information because their school doesn’t have enough paper to make copies.

“We have only one science teacher for the entire(整个的) high school,” writes Felix Ruano, a 16-year-old student. He goes on to describe how that teacher, who is only qualified to teach chemistry, is teaching physics — or, at least, is trying to do so. “He shows physics videos and we teach ourselves from our textbook,” says Ruano. And, as has been seen elsewhere, “all but one of the restrooms” at Ruano’s school “have been closed because we don’t have enough people to clean them.”

Ruano notes that though faced with the challenges, 97 percent of students say they plan to go to college. But without “properly trained teachers and the best resources,” says Ruano, it’s not likely that every student will achieve that goal. “Unless schools fix these problems,” he says, “students could lose hope.”

小题1:According to the text, education cuts have led to the following results EXCEPT that _____.

A.class sizes at some high schools have risen

B.some students don’t have a desk to sit at

C.some students have to share textbooks

D.some students have to leave school小题2:The underlined word “qualified” in the fourth paragraph can best be replaced by “_____”.

A.fit

B.willing

C.bored

D.worried小题3:According to Ruano, _____.

A.he is good at teaching himself

B.most students plan to go to college

C.his school is going to be closed

D.most students are hopeful about their school小题4:What would be the best title for the text?

A.What caused education cuts?

B.Education cuts, right or wrong?

C.Education cuts have hurt students

D.How to deal with education cuts

单项选择题