按要求改写句子

1. That is an English book.(对划线部分提问)

    ______ ______ in English?

2. The is an orange.(改为复数句子)

    ______ ______ oranges.

3. His backpack is on the chair.(对划线部分提问)

    ______ ______ his backpack?

4. He has a tennis racket.(改为--般疑问句)

    _____ he _____ a tennis racket?

5. -Are those your sisters?(作否定回答)

    -No, ______ ______

一个n×n的对称矩阵，如果以行为主序或以列为主序存入内存，则其容量为______。