检测水中的细菌学指标时,每次试验要以无菌水为样品,对培养基、滤膜、稀释水、玻璃器皿和冲洗用水做无菌性检验。
参考答案:对
It’s a fine day. Let’s go fishing, _____.
A.won’t we
B.will we
C.don’t we
D.shall we
—Are Mr. and Mrs. Wang living alone in the house?
—Yes, altough they have three sons, ______ of them live with their parents. [ ]
A. neihter
B. both
C. all
D. none