下列关于细胞免疫的叙述，错误的是[ ]

A．进行细胞免疫时，抗原需要被吞噬细胞摄取和处理

B．细胞免疫主要消灭侵入人体细胞内部的病原体

C．记忆T细胞接受同一种抗原刺激的再次刺激后，会迅速增殖并分化成效应T细胞

D．效应T细胞可以直接杀伤抗原

按要求做题。    

1. It seems that Polar Bears are gentle animals. (同义句)       

    Polar Bears seems ____                   gentle animals.    

2. I am like this animal because I am strong and intelligent.  (对划线部分提问)       

                are you             this animal?     

3. The bridge was built last year. This photo was taken there. (合并成定语从句)       

    The bridge___      this photo was taken             _____ last year.    

4. The question isn’t easy enough for them to answer. (改为复舍句)   

    The question is             _____ _____ they             answer it.    

5. I really don’t know which sweater I should buy. (改为简单句)      

    I really don’t know ______ ______  to______.