I had walked a few steps _______ I realized that I was lost in the thick fog.
( ) 29. In such dry weather, the flowers will have to be watered if they _________.
( ) 28. Things fall to the ground _______ go up into the air because of gravity.
( ) 27. Take _______ half, they’re exactly the same.
( ) 26. I have been studying computer for several years and I still __________.
( ) 25. This book is said to be a special one , which _______ many events not found in other history books.