He felt very happy, because he ______ the exam.

用所给的单词的适当形式填空

①This is the ____ (one) time for me to see you.

②November is the ____ (eleven) month of the year.

③  My ____ (sister) birthday is on November 12.

④  September 10 is ____ (teacher) Day.

⑤  ____ (she) birthday is on May 5.

⑥  The ____ (five) lesson is very interesting.

水分从土壤进入根毛的途径（　　）

60+7=____           75-5=____               20+30+40=____

50+21=____         76+9=____              4+（9+20）=____

29+6=____           86-30=____              66-6-50=____

100-10=____        81-（7+3）=____     83+10-50=____

一艘轮船从甲地到乙地每小时航行30千米，然后按原路返回，若想往返的平均速度为40千米，则返回时每小时应航行____千米．