Question

What's this?的答句为It's a 什么还是It's 什么。（可数名词情况下）

Answer 1

可数名词情况下，有两种回答：

1. 名词是可数单数且以元音音素开头时，用It's an....  如：It's an orange/eraser/apple.

2. 名词是可数名词单数且以辅音音素开头时，用It's a.... 如：It's a cup/book/glass.

Answer 2

What's this?的答句为It's a 什么还是It's 什么。（可数名词情况下）

(1) What's this : It's an apple (元音发音）

(2) What's this : It is a book （辅音发音）

Answer 3

当然是 It‘s a / an ....；
如：What's this? It's a book / an apple.

Answer 4

如果是可数名词的话，我的建议是It's a...

Answer 5

应该是
It's a