泥浆护壁通常采用塑性指数大于30的高塑性黏土。

A 10-year-old boy decided to study judo (柔道), although he had lost his left arm in a car accident.

　　The boy began lessons with an old Japanese judo teacher, Mr. Tanaka. The boy was doing well, but his teacher had taught him only one move in three months of training.

　　“Mr. Tanaka,” the boy finally asked, “shouldn’t I be learning more moves？”

　　“This is the only move you know, but this is the only move you’ll ever need to know,” his teacher replied.

　　Several months later, Mr. Tanaka took the boy to his first tournament (锦标赛). The boy won his first three matches, using his one move to win. The boy was now in the finals, and was amazed by his own success.

　　This time, his opponent (对手) was bigger, stronger, and more experienced. The referee (裁判) wanted to stop the match.

　　“No,” the teacher insisted, “let him continue.” Soon, his opponent lowered his guard. At that moment the boy used his move to pin (钉住) him. The boy won the match and became the champion.

　　On the way home, the boy and his teacher reviewed every match. Then the boy asked what was really in his mind.

　　“Mr. Tanaka, how did I win the tournament with only one move？”

　　“You won for two reasons,” his teacher answered. “First, you’ve almost mastered one of the most difficult throws in all of judo. And second, the only defense (防守) for that move is for your opponent to catch your left arm.”

　　The boy’s biggest weakness had become his biggest strength (优点).

小题1:The boy decided to study judo though ____________.

A．he was only ten years old

B．he would have an old teacher

C．he had lost his left arm in a car accident

D．he knew he was not clever小题2:How did the boy feel when he was in the finals？

A．Proud.

B．Surprised.

C．Worried.

D．Happy.小题3:What can you infer (推断) from the passage？

A．The boy wasn’t doing well at first.

B．Mr. Tanaka is a good teacher because he knows his student’s strength and weakness.

C．The referee believed the boy would win.

D．The boy had predicted that he would win.

如图甲所示是测量定值电阻R的实物连接图（缺一根导线）．图中R约为10 Ω，滑动变阻器R'的规格为“20 Ω 1A”．

（1）请在图甲中接上滑动变阻器，要求滑片P在A端时接入的阻值最大．

（2）正确连接好电路后，闭合开关，调节滑动变阻器，使电流表的示数为图乙所示，其读数为 _________ A．

（3）实验中滑动变阻器的作用是_________（填一项即可）．

（4）若在实验中发现电压表已损坏，仍利用该电路测出定值电阻R的阻值．要求写出实验步骤及所测的物理量，并以相应的符号表示．

步骤1：_________；

步骤2：_________；

步骤3：根据以上测出的物理量及题中的条件，用相应的符号写出计算电阻的表达式：R=_________．

小明出去散步前看了一下手表，回来时又看了一下手表，发现此时手表的时针，分针的位置正好与出去时的分针，时针位置相同．若他在外逗留的时间不足一小时，则他在外待了______分钟．

滚动摩擦表面粗糙度值要（）滑动摩擦表面的粗糙度值。

A.高于

B.低于

C.等于

D.大大高于

小组目标