20.Below are some smart ways to stay smart suggested by some American experts.
46.According to the writer,the real reason for minimizing television watching is thatD.
A.people will weaken a muscle for lack of enough exercise
B.people have no time to talk with their friends or families
C.people are too tired to fix their eyes on their books or work
D.people don't do mental activities or refresh themselves
47.The common feature between Take More Exercise and Early to Bed,Early to Rise is thatA
A.both make people concentrate more easily
B.they help people to have a good sleep
C.each make people learn and eat more
D.they may reduce study time and efficiency
48.Which of the following is not the advantage of reading challenging books?C
A.It promotes people's thinking.
B.It improves people's writing.
C.It saves people's mental labor.
D.It increases people's motivation.
49.Which of the following best explains the sentence"The best means is taking a single walk."?B
A.A walk is the best exercise.
B.A walk helps to reflect clearly.
C.A walk relieves loneliness.
D.A walk gives people much pleasure.