It’s no use ________ without taking action．[ ]

Next, John Snow ______ the source of the water for these two streets and found it came from the polluted river.

man has his faults. We should, therefore, learnto be ________ of others.

I would have come earlier, but I _____ that you were waiting for me[ ]

More and more high-rise buildings have been built in big cities ______ space．