北魏孝文帝改革的根本目的是[ ] A．恢复和发展北方经济以稳定统治 B．接受汉族

人的手上有许多关节，以这些关节为枢纽可以做各种比较精细的动作，你认为这些关节在运动中起的作用是（　　）

A．支点作用

B．动力作用

C．调节作用

D．杠杆作用

单克隆抗体(单抗)实质上是单个效应B细胞通过克隆形成的细胞群产生的化学性质单一、特异性强的免疫球蛋白。下列有关叙述中，错误的是[ ]

A．单抗作为生物导弹能定向到达癌细胞所在部位

B．单抗制备的过程要用到动物细胞培养和细胞融合技术

C．在单抗制备的过程中必须经过至少两次细胞筛选

D．只有用物理或化学方法的诱导，才能促使B淋巴细胞与骨髓瘤细胞融合形成杂交瘤细胞

常用温度计是根据_____ 原理制成的，如图甲中温度计的示数是_____℃，乙中的示数是

_____℃。

我国土地资源的重要特点是[ ]

A、总量多，人均少

B、总量少，人均也少

C、总量多，人均也多

D、总量少，人均多

How did the Olympic Games start In ancient Greece athletic festivals were very important and had p ________ (1). Originally the Festival was held in honour of .Zeus, the supreme god in Greek Mythology. Eventually the Olympian athletic festival had lost its ________ (2) and became an international event. No one knows exactly ________ (3) the Olympic Games go, but some scholars recorded date from 776 B.C.According to some scholars, at first the only Olympic event was ________ (4), called a stadium and that was the only event until 724 B.C. After that, other ________ (5) were added and sixteen years later in ________ (6) the pentathlon was added and wrestling became part of the games. This pentathlon was a five-event match which ________ (7) running, wrestling, leaping, throwing the discus, and hurling the javelin.The games were held ________ (8) and after an uninterrupted history of 1170 years, the games ________ (9) in A.D. 394, the Christian era, because of their pagan origin.It was over ________ (10) before there was another such international athletics gathering. In 1896, the first of the modern ________ (11) opened in Athens, Greece.Nowadays, the Games are held in different countries ________ (12). The host country provides vast facilities such as stadiums and ________ (13).Many more sports are represented, including the very celebrated event: ________ (14).The Olympics start with the arrival in the stadium of a torch, ________ (15) on Mount Olympus by the sun’s rays. The torch is carried by ________ (16) to the stadium. The Olympic flame symbolizes the ________ (17) of the ancient Greek athletic ideals, and it burns throughout the Games until ________ (18). The well-known Olympic flag, however, is ________ (19): the five interlocking rings symbolize the uniting of all five continents ________ (20).