A:is playing
B:play
C:are playing
It's reported that the passenger ship "Eastern Star" capsized and sank(翻沉) in the Yangtze River _____ June 1st, 2015.
下列选项中有利于培养我们自尊心的是 ( )
电镀是金属防锈的方法之一.某兴趣小组同学用标为A、B、C的三只试剂瓶,从电镀厂取来ZnSO4、CuSO4和AgNO3三种电镀液.由于忘记每瓶中装的是何种溶液,所以分别取出三种电镀液进行了探究.
根据以上实验回答:
a、b两城夏至日和冬至日正午旗杆(等高)的影长及朝向如图,据此回答下题.