胰头癌主要的临床表现是（） A.上腹痛 B.黄疸 C.腹胀 D.便秘 E.腹泻

1.       to speak English all the time in class.
2.When your teacher asks you a question,       your answer.
3.If you        in English study,you will improve your English and love it very much.
4.       remember eight or ten words a day.
5.My teacher gave me some advice and I         it       in my study daily.
6.We        camping this Sunday.
7.       writing down your mistakes.
8.You should        the manager about it.
9.Sometimes I       my old friend and        other things to write a letter.