问题
选择题
I'm going to the bookstore ____________ subway. [ ]
A. on
B. by
C. in
答案
答案:B
I'm going to the bookstore ____________ subway. [ ]
A. on
B. by
C. in
答案:B
在“探究杠杆平衡条件”的实验中:
(1)首先应调节______,使杠杆在水平位置平衡.
(2)实验数据如下表所示,通过分析实验数据可得出的结论是:______.
(3)完成表格.
次数 | 动力F1/N | 动力臂l1/cm | 阻力F2/N | 阻力臂l2/cm |
1 | 1 | 2.0 | 0.5 | 4.0 |
2 | 2 | 3.0 | 3 | 2.0 |
3 | 3 | 2.0 | 2 | ______ |