水准仪应尽可能安置在前、后视点的____。
在水准测量中,若后视点A的读数大,前视点B的读数小,则有________。
You can _____ some bottles of wine, or some chocolates, or a bunch of flowers.
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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