用所给词的适当形式填空。

1.—What ________ you ________now?

  —I ________ (make) a cake for my birthday.

2.  Paul can't ________(go) to the party.

3.  How________you________ (spend)  your last weekend?

4.  The day after tomorrow I ________to the mountains.

5.  —Can she go to the baseball game this morning?

    —No, she can't. She ________ (have) a computer lesson.

6.  Please________ (not talk) to Jim.  He is doing his homework.

基因治疗主要是对哪种细胞进行修复的（）

A.有缺陷的细胞

B.有基因缺陷的细胞

C.癌细胞

D.正常细胞