poor at English, I'm afraid I can't make myself .
A. To be; understand
B. I'm ; to understand
C. Being; understanding
D. Being; understood
网友回答
A. To be; understand
B. I'm ; to understand
C. Being; understanding
(答案→)D. Being; understood
解析：考查非谓语动词。因为中间是逗号，表明前面不是一个句子，故排除B，to be poor，常表示目的，故排除；第二格，make oneself done，使自己被…；故答案为D。