what is in your pencilcase 这个句型里what 是主语吗

What is your brother doing?He is writting ___.A by a pencilB with penC in a paperD in a book what is in your What is in your hand, what is in your hand? what is in your school? what is your aim in what is in your school put the ( )in the penc-case The ( )is on the desk what is your life?what is important in your life? put the ( )in the penc-case What room in your home is your computer in? What is in your schoolbag什么意思 is your in schoolbag what 造句 What is in your school bag?改错 what is that in your hand? I have what is in your eyes? What is in your school bag?改错 what weather is today in your there?