PresidentXiJinpingdemandedthattheenvironmentalproblems

问题详情：

President Xi Jinping demanded that the environmental problems ______ paid special attention to.

   A. referred to being                                         B. referred to be

   C. refer to being                                              D. refer to be

【回答】

B

知识点：非谓语动词

题型：选择题