It is human activities on the earth that are to _______ global warming.

fashion news about skirts— Yes This season’s short skirts have gainedpopularity now, although they tobe shocking at first

Occasions are quite rare _____I have the time to spend a day with my kids.

Mary ______late for class. Now she is in the classroom.

What is the price of petrol these days? —Oh，it ________ sharply since last month