句型转换   根据括号内的要求改写句子，在答题卷相应的横线上填写答案，每空限填一 词。（本大题共5分，每格0.5分）

小题1:What does this sentence mean? (保持意思基本不变)

What is the     1        2    this sentence?

小题2:When the twin sister Huihui was born, she weighed just 1950 grams. (保持意思基本不变)

The twin sister Huihui weighed just 1950 grams     3        4   .

小题3:Mr. White goes to Zhalong to watch birds once a year. (对划线部分提问)

    5        6    does Mr. White go to Zhalong to watch birds?

小题4:We bought a special program in order to help the computer recognize our voice. (对划线部分提问)

    7    did you     8    a special program?

小题5:He can’t finish the work in such a short time. (保持意思基本不变)

    9        10    for him to finish the work in such a short time.

DNA复性是指（）

A.不同的核酸链经变性处理，它们之间形成局部的双链

B.一小段核苷酸聚合体的单链，用放射性核素或生物素来标记其末端或全链

C.运输氨基酸

D.单股DNA恢复成双股DNA

E.50%双链DNA变性时的温度