资源简介
（友情提示：鼠标拖选单词即时翻译）
用since 和for填空（10分）
1.They have been learning Chinese ________they came to China.
2. I haven’t seen her _______ 10 years..
3. He has been living here _______ 2001.
4. She has been doing her homework _______two hours.
5. – How long has Mary been a teacher?
– _______last year.