单项选择题
Humans should not develop their economy at the （） of the ecological envi ronment.
A．destruction B．pollution C．expense D．mercy
单项选择题 As we can no longer wait for the delivery of our order, we have to （） it.
单项选择题 The car one drives may show his/her （） or social position.
单项选择题 Why are some of us good at math, or writing, while others （） at art or basketball
