30. He is badly down these days. This sentence probably means _____.
The headmaster hurried to the concert hall only ________ (find) the speaker ________(go).
After many years' hard work, she now is pleased ________ playing almost all kinds of music.
Every day a number of tourists take pictures in front of the tower, which dates ________ as early as 800 years ago.
________ (assume) that we can't get the necessary equipment, we will have to give up the experiment.
—Was the driving pleasant when you went to Mexico last summer? —No, it ________ (rain) for four days when we arrived, so the roads were very muddy.