The country has already sent up three unmanned spacecraft，the most recent ________ at the end of last March.

--- Have you got any books on English grammar? I’d like to borrow         .--- Yes, here you are. But you must return it by Friday.

I saw a lighthouse _____ at the mouth of the river.

_______ in the war, many children have become orphans(孤儿).

The sunlight is white and blinding _______ hard-edged shadows on the ground.