设向量组(1)α1，α2，…，αs，其秩为r1，向量组(2)β1，β2，…，βs，其

现阶段在软弱地层中修建地铁和交通隧道以及各种用途管道最先进的、应用广泛的施工方法之一是（）。

A.沉管法

B.盾构法

C.掘进机法

D.钻爆法

根据句意及首字母提示在横线处填上恰当的单词，使句子意思完整，语法正确。

1.  He sits b_______me now, but he used to sit between Tom and me.

2.  Go p_______the bank, and you will find it on your right.

3.  I hope that I can see Liu Qian performing_______.

4.  You can take the e_______to the second floor.

5.  He wants to buy a bottle of s_______to wash his hair.

6.  Is there a r_______where I can wash hands near here?

7.  You can have nice coffee at the c_______.

8.  I saw him buy some medicine in the d_______.

9.  We live in the same b_______.I often visit him.

10. The d_______store is having a sale.  There are many people there.

如图所示，水平面上有一物体，人通过定滑轮用绳子拉它，在图示位置时，若人的速度为5 m/s，则物体的瞬时速度为___________m/s。

Happy birthday, Alice! So you have               twenty-one already.     [      ]

A．become          

B．turned    

C．grown            

D．passed

心肌细胞分为快反应细胞核慢反应细胞的主要分类依据是（）

A.4期自动去极化的速度

B.静息电位及最大复极点位数值

C.动作电位时程长短及幅度

D.0期去极化的速度

E.动作电位复极化的速度