this is an apple 这是一个苹果,改为疑问句is this an apple?这是一个苹果吗?请问这样改对

this is an apple 这是一个苹果,改为疑问句is this an apple?这是一个苹果吗?请问这样改对 把This is an apple改为一般疑问句 This is an apple 改为否定句,怎么改? 填空要求,It is （ ）apple .（这是一个苹果.）是应该填上an 还是one What colour is it?What colour is this apple?请问这是特殊疑问句吗? 一个苹果或一个梨是an apple and a pear 还是an apple and pear? this is an apple 和 this is apple 哪个语法是正确的 ls this an apple?的肯定回答是Yes,this is an apple.还是Yes,it is an a is this an apple an orange__an egg This is an apple就an apple部分转换提问 一个红色的苹果 是a red apple 还是 an red apple 并且说出为什么 一个大苹果是What a big apple还是What an big apple