18.In this experiment, they are woken up several times during the night, and asked to report what they _______.
Now a lot of new technologies can ___________ problems in industry.
________ entered the classroom _________ the bell rang.
So loudly ______ that every one of the class could hear him.
---What do you think made her so upset? ---_____________ her hometown.
Though ___________ to see us, the professor gave us a warm welcome.