A:(﹣∞,1)
B:(﹣∞,2)
C:(1,2)
D:1,2)
-- English is widely used all over the country.
-- Yeah, it is such ______ useful language that my grandma decided to buy ______ English-Chinese dictionary to learn it.
选用显微镜的5×目镜.40×物镜,该组镜头能使物像放大()