I have received （） professional training.

单项选择题I think your sister is old enough to know （） to spend all her money on fancy goods.

A.better than
B.than
C.other than
D.rather than

单项选择题In addition to setting the price of a product, business firms must decide （） to offer special discount and credit terms to their customers.

A.if
B.which
C.whatever
D.whether