将下列句子时态改正确拜托各位大神

将下列句子时态改正确拜托各位大神
1:When I saw Mary,she is playing on the piano.2:I will take my daughter with me when I am going to Shanghai.3:It's spring now.Students plant trees these weeks.4:They have gone to the Summer Palace three times.5:By this time next year,he will graduate from college.6:The volleyball game will be put off if it will rain.7:The students had written busily when Miss Brown went to get a book.8:You don't need to describe her.I met her several times.9:-Oh,it's you!I don't recognize you.-I've just had my hair cut,and I'm wearing new glasses.10:The teacher told the children that the sun was round.