there must be
（A）at least one maple
（B）at least one red oak
（C）at least one sycamore
（D）at most one maple
（E）at most one red oak
22.If maples are planted， the side of the street that has
four trees must have
（A）red oaks in positions 1 and 7
（B）red oaks in positions 3 and 5
（C）sycamores in positions 1 and 3
（D）sycamores in positions 1 and 7
（E）sycamores in positions 3 and 5
23.A list of the fifteen operas most frequently performed
in recent times includes no works by the nineteenth-
century German composer Richard Wagner. Although
music producers tend to produce what audiences want，
relative infrequency of performance probably does
not indicate lack of popularity in Wagner s case， since
Wagner s operas are notoriously expensive to perform
on stage.
Which of the following， if true， most strongly
supports the conclusion of the argument above？
（A）The list of most frequently performed operas
does not include operas produced by small
amateur groups.
（B）Some opera companies are backed by patrons
who are willing to commit large sums of
money in order to enjoy lavish productions.
（C）All of the fifteen most frequently performed
operas of recent times are works that have
been popular for at least 75 years.
（D）More recordings have been produced recently of
the works of Wagner than of the works of any
other composer of opera.
（E）Operatic works of all kinds have been increasing
in popularity in recent years.
