大家帮我看几道英语语法题需要正确率谢谢

大家帮我看几道英语语法题需要正确率谢谢
Snow _______ steadily in this city since early this morning and the meteorologists say that it will continue until tomorrow afternoon.
had fallen
had been falling
is falling
has been falling
Because of the storm,most offices _______.Most workers are now home or on their way home.
close
have closed
had closed
had been closing
Essential services,however,remain open,and city employees _______ steadily to clear the snow off the major roads.They'll continue working throughout the night on this difficult task.
had worked
had been working
worked
have been working
This _______ the worst snowstorm in the area for the past decade,and it's not over yet!
has been
was
had been
have been
Even early this morning,the streets were practically empty of traffic because most people _______ of the storm on news reports yesterday evening.
have learned
have been learning
had learned
had been learning