It was several minutes ________ we realized what was happening—our dog was trapped in a newly－dug tunnel.

I ______ make a home page three years ago, but now I am good at it.

We drove to the airport to meet an expert from Germany, about 50 years old, his hair ________.

____________________________—– It’s black, B-L-A-C-K, black.

I ______________ have passed my examination easily，but I made too many stupid mistakes