_______ caused the accident is still a complete mystery.
Wastes from the factory ______the water pollution in this area.
---Oh, you’ve got this English-Chinese dictionary. How do you find it? ----It is ______. I turn to it whenever I meet with new words.
Chinese differs from western languages ______ it uses characters ______ stand for ideas, objects and deeds.
Reaching out ______ the money in the shop, the thief heard a strange sound and was sweating ______ fear.
Polly’s mother was anxious about ______ she could get home safely in ______ foggy a day.