问题
选择题
At times this balance of nature is ____, resulting in a number of possibly unforeseen effects. [ ]
A. troubled
B. confused
C. interrupted
D. disturbed
答案
答案:D
At times this balance of nature is ____, resulting in a number of possibly unforeseen effects. [ ]
A. troubled
B. confused
C. interrupted
D. disturbed
答案:D
在表中列出了几种物质中的声速(m/s):你发现的物理规律有:
空气(15℃) | 340 | 海水(25℃) | 1531 |
空气(25℃) | 346 | 钢(棒) | 3750 |
软木 | 500 | 大理石 | 3810 |
煤油 | 1324 | 钢(棒) | 5000 |
蒸馏水 | 1497 | 铁(棒) | 5200 |
(2)______.