请大家帮我分析几个英文句子1. I got a letter from Partricia this morning,

请大家帮我分析几个英文句子
1. I got a letter from Partricia this morning, _____ she is expecting another baby.
A. saying B.writing C. telling D. speaking
2. I _____ the dishes this morning.
A. have washed B. wash
C. had washed D. washes
3. Can you _____ him to take part in the activity?
A. talk B. speak C. persuade D. tell
请帮我分析下第一题的四个答案,第二题为什么选A ,不选C呢?第三题我觉得C 和 D 都可以选,但是正确答案上面选C,能帮我分析一下吗?谢谢