How long have you been studying?
How long have you been studying English?
How long have you been studying?
HOW long have you been studying english 怎么回答
how long have you been studying为什么后面要加ing
"How long have you been
How long have you been skating?
how long have you been playing basketball ?
How long have you been swimming?
How long have you been ____?
1.How long have you been here?
how long have you been ---work?
“How long have you been watching