A:美元升值→中国商品在美国市场的价格下降→不利于中国商品出口美国
B:美元贬值→美国商品在中国市场的价格上升→有利于中国进口美国商品
C:人民币升值→中国企业在美国投资成本下降→有利于中国企业在美国投资
D:人民币贬值→中国企业在美国投资成本上升→不利于中国企业在美国投资
如果两个变量的散点图由左下角到右上角则这两个变量成____相关.
下列各混合物中,用分液漏斗不能分开的是( )
In our city there are more and more cars and buses on the roads. Many people drive to work .First, it's good to have a car. You needn't to wait for the bus. You can go to work on time. Then ,there are many busy roads in the city . Can you drive safely? Traffic lights are very important. You must look at the traffic lights and wait for the green man. If someone is crossing the road, you must stop your car and look carefully. We must follow the rules and stay safe on the road.