A．Because they are too lazy to write down too many words.
B．Because they write slower than they type.
C．Because they can't remember all the words.
D．Because they can't understand what the teacher says.
A．Turn off the computer and write notes by hand.
B．Write down what the professor says word-for-word.
C．Type slowly to summarize the main points.
D．Use some technologies for writing notes by hand on computers.
A．People seldom talk about happiness these days.
B．The number of books with "happiness" in the title is less than 40.
C．There is a huge wave of interest in happiness among researchers.
D．There are a few traps that make it possible to think straight about happiness.