A:①②
B:③④
C:①③
D:②④
–I like the weather in Kunming. It's warm all year long.—Yes. And the temperature stays zero all the time.
阿强在显微镜下观察玻片时,在视野中看到有一黑点,转动目镜和移动装片,黑点都没有发生位移,因此可以断定黑点最可能是在( )
80×3.5÷(0.4×0.7)=____