（）是电子商务所具优势正常发挥的保证。A.信息流 B.资金流 C.物流 D.商流

Wu Juping is just a saleswoman. However, on July 2, 2011, she bravely caught a falling child and has been praised as the most beautiful mother in China. The child fell from the 10^th floor of a building into Wu’s arms.

The child is two years old, who named Niu Niu. Niu Niu climbed up to the window looking for her grandma. When a neighbor living one floor saw the little girl falling, he held out a ladder(梯子) to catch her. The ladder, however, was too short to reach the girl. At this dangerous moment, Wu, who was just walking near the building, rushed to the spot and caught her successfully before she hit the ground.

The girl fell into coma(昏迷), and Wu was also injured seriously in her left arm. On July8, Niu Niu, who was able to move her fingers, feet and eyes, was out of dangerous condition and Wu’s arm is recovering well now.

根据短文内容回答下列问题。（每题2分，满分10分）

小题1: What does Wu Juping do?

小题2: When did Wu Juping save the child?

小题3: Why did the child fall from the 10^th floor of the building?

小题4: What did the neighbor do when he saw the girl falling?

小题5: Was the girl out of dangerous condition in the end?

如图所示为一质点运动的速度--时间图象，曲线为一正弦曲线的上半部，则在0～t₁这段时间内（　　）

A．质点的速度先减小后增大

B．质点在t₁时刻离开出发点最远

C．质点运动的加速度先增大后减小

D．图中正弦曲线是质点的实际运动轨迹

杂交瘤细胞株常用的保存方法是 （）

A.4℃冰箱保存

B.37℃保存

C.-20℃保存

D.-30℃保存

E.液氮（-190℃）保存

下列图中，哪一个结构在支座位移后产生内力(提示：结构自重不计)（）

A.A

B.B

C.C

D.D

四时捺钵