2.1 Fill in the following blanks with “first” or “at first” as you see fit.1. Labor Day in the US falls on the ____ Monday in September.2 The speaker seemed a little nervous ____ , but after a short while became relaxed (放松).3 You want to learn making Chinese dumplings (饺子)? ___ of all, let me show you how to make dough (面团).4 It was sunny but cool when we started. So the journey was quite pleasant ____. Then all of a sudden there came a thunderstorm.2.2 Fill in the following blanks with “resource(s)” or “source(s)” as you see fit.1. Canada is a country rich in natural _____ .2. The travelers walked upstream until they reached the _____ of the river.3. So far there has been no response (回应) from official _____.4. With such limited (有限的) _____ , the manager has been doing remarkably well to keep the organization going.