I'm afraid ______ (lose) my key.I can't find it now

I'm afraid ______ (lose) my key.I can't find it now
I'm afraid ______ (lose) my key.I can't find it now

I'm afraid ______ (lose) my key.I can't find it now
正确：I'm afraid I have lost my key.I can't find it now.
注：英语为母语的人中绝不会有任何一个人会说成以下两种中的任何一种：
I'm afraid to have lost my key.I can't find it now.
I'm afraid of having lost my key.I can't find it now.