Ответ:
1. The influx of foreign students brings in an additional 1.5 billion dollars a year to the American economy.
Does the influx of foreign students bring in an additional 1.5 billion dollars a year to the American economy?
How much money does the influx of foreign students bring to the American economy?
How often does the influx of foreign students bring in an additional 1.5 billion dollars to the American economy?
The influx of foreign students brings in an additional 1.5 billion dollars a year to the American economy, doesn't it?
Does the influx of foreign students bring in an additional 1.5 billion dollars or 2.5 billion dollars a year to the American economy?
2. The easiest way to travel around London is by bus
Is the easiest way to travel around London by bus?
What is the easiest way to travel around London?
How can you travel around London?
The easiest way to travel around London is by bus, isn't?
Is the easiest way to travel around London by bus or by cab?