日光下澈，影布石上，（）；俶尔远逝，往来翕忽，似与游者相乐。。

Like schools in China, American schools begin in September after a long summer vacation. The first term is from September to January and the second is from February to June. Usually American children begin to go to school when they are five years old. Most students are seventeen or eighteen years old when they finish high school.

But unlike middle school students in China, high school students in America take only four or five subjects each term. They usually go to the same classes every day and have homework for every class. After class they do all kinds of interesting things.

After high school, many students go to college. They may go to a small or a large one. They usually have to pay a lot for their higher education. So lots of students work after school to make money for their studies.

小题1:In America, summer vacation lasts（持续）___________________.

A．one month

B．two months

C．three months

D．more than three months小题2:The underlined（下划线的）word “college” means _________________ in Chinese.

A．大学

B．公司

C．研究院

D．高中小题3:Many American students work after class, because they ___________________.

A．want to see interesting things

B．have to help the other people

C．want to make more friends

D．have to get money for their studies

牙面清洁后到新的牙菌斑成熟，可被菌斑显示剂着色的时间大约为（）

A.2小时

B.12小时

C.9小时

D.2天

E.12天

下列关于细胞学说的叙述，错误的是（）。

A.1665年，英国科学家罗伯特·虎克发现了细胞，并创立了细胞学说

B.细胞是一个有机体，一切动植物都由细胞发育而来，并由细胞和细胞产物所构成

C.细胞是一个相对独立的单位，既有它自己的生命，又对与其他细胞共同组成的整体的生命起作用

D.新细胞可以从老细胞中产生

氯丙嗪阻断中脑-边缘系统和中脑-皮质系统中D₂受体可产生

A．抗精神病作用
B．镇吐作用
C．体温调节失灵
D．帕金森综合征
E．巨人症的治疗

男，59岁，右侧髋骶部持续性疼痛，夜间加重。2月前被确诊为肾细胞癌，结合图像，最可能的诊断是（）

A.骨肉瘤

B.骨巨细胞瘤

C.骨囊肿

D.骨转移瘤

E.骨瘤