下图为某病毒侵入机体被杀伤过程图解，据图回答：
靶细胞裂解后，要进一步清除抗原往往需要与（）免疫相结合。
参考答案：体液
关系运算中的选择运算是( )。
A) 从关系中找出满足给定条件的元组的操作B) 从关系中选择若干个属性组成新的关系的操作C) 从关系中选择满足给定条件的属性的操作D) Ａ)和Ｂ)都对
句型转换
1. Mr More stays in Shanghai for three days. (就画线部分提问)
______ ______ ______ Mr More ______ in Shanghai?
2. They enjoyed themselves in the park. (改为同义句)
They ______ ______ ______ ______ in the park.
3. Lin Tao did the housework at home last night. (改为否定句)
Lin Tao ______ ______ the housework at home last night.
4. I sometimes watch TV in the evening. (就画线部分提问)
______ ______ do you watch TV in the evening?
5. The twins are going to Hong Kong the day after tomorrow. (改为一般疑问句)
______ the twins ______ ______ Hong Kong the day after tomorrow?
