原式=1-1-3-2+3,
=-5+3,
My uncle is not rich, but he has many books in ______ room.
A. he B. his C. him
既有保持原料中营养物质又能有效抑制微生物、细菌、活性酶的pH值是()。
A、3~4
B、5~6
C、7~8
D、9~10