①对他来说像以前一样频繁的看到他们是不容易的。
②我的妹妹加入阅读兴趣小组2个月了。(3种)
③那家店投入使用3年了。
④你的朋友离开北京多久了。
①It__ __ ___ him __ see them __ often __ before.
②My sister __ __ __the Reading Club __for 2 __
My sister __ __ __the Reading club __2__ __
My sister __ the Reading club two __ __.
③The shop __ __ __ __ __3 years
④__ __ __ your friend __ __ __ Beijing?