Scientists have long struggle with how to measure the effects of climate change on wildlife.
Scientists have long struggle with how to measure the effects of climate change on wildlife.
现在
_____ it is very late now, the researchers are still working in the lab.
\_\_\_\__ it is very late now, the researchers are still working in the lab.
The number of primary schools in the rural areas _____ doubling in the past 50 years.
The number of primary schools in the rural areas \_\_\_\__ doubling in the past 50 years.
He _____ from college three years ago, but now he is the boss of a large business.
He \_\_\_\__ from college three years ago, but now he is the boss of a large business.
I have lived in this city thirty years ago, so I know it quite well.
I have lived in this city thirty years ago, so I know it quite well.
The Third City Hall is now used as a _____.
The Third City Hall is now used as a \_\_\_\__.
Professor Morison has never been to China, nor does Dr. Jones.
Professor Morison has never been to China, nor does Dr. Jones.
He has come to work for a local newspaper about ten years ago, when he graduated from Peking University.
He has come to work for a local newspaper about ten years ago, when he graduated from Peking University.