单项选择题
Since the new technology was introduced last month, we（）in speeding up production.
A．succeed B．succeeded C．have succeeded D．will succeed
单项选择题 Before the age of the Internet, we used to（）our holidays through travel agents.
单项选择题 Now the air pollution in this city（）more and more serious with each passing day.
单项选择题 The manager said that there were two reasons（）our sales dropped sharply last year.
