we have done a lot to build a low-carbon economy, but it is________ idealWe have to work still harder

Over the past 20 years the once-sleepy fishing village ______ into an international tourism destination, with many visitors coming to explore its spectacular rainforests and beaches

The money he spent within a month _________ more than 1,000 dollars.[ ]

The number of students in our school____about 30,000 and ______them study hard.

Is Professer Smith giving the speech today?–It ________ be him. He is abroad right now.