炉管的传热量一定时,炉管的表面积与表面热强度之间是()关系。
A、成平方
B、成反比
C、成正比
D、无法确定
参考答案:B
1. China’s Opening-up Policy(开放政策)encourages more people to learn English.
2. China’s entry into WTO encourages more people to learn English.
3. Beijing’s successful bid for the 2008 Olympic Games encourages more people to learn English.
把490分解质因数是______.