单项选择题
The struggle against sand storm will not end ______ victory unless we pay much attention to the balance of nature.
单项选择题 Was this piece of earthenware(陶器) made ______ machine or ______ hand
单项选择题 Our music teacher often enjoyed ______ playing the violin in his spare time.
单项选择题 We shall have finished this course ______ the end of this term.
