题目：
Our country, together with others in the Third World,________ hard to build a harmonious homeland
for human beings now.[ ]
A. work
B. working
C. is working
D. are working
答案：
答案：C
Our country, together with others in the Third World,________ hard to build a harmonious homeland
for human beings now.[ ]
A. work
B. working
C. is working
D. are working
答案：C
堂就珠江和黄河这两条河进行相关资料的收集和处理，并列表比较这两条河的水文特征和水系特点。假如你是其学生中的一员，完成1～2题。