【单选题】下列生物学实验操作,不合理的是
A.
分离色素时,往试管中加入层析液,使液面高度低于滤液细线
B.
使用血球计数板计数酵母菌时,要先将培养液混合均匀再取出
C.
鉴定酒精时,可以直接将重铬酸钾溶液滴入待测溶液观察颜色变化
D.
观察洋葱根尖有丝分裂时,解离之后经过漂洗就可以用龙胆紫溶液染色
【多选题】商务人员出入宾馆时,门童为你开启大门,或向你问好,应( )
【判断题】酱醪经生化变化,产生各种蛋白质和淀粉的分解产物并合成一些产物,这些物质的综合作用构成了酱油特有的风味和性状。
【单选题】All flights ______ because of the snowstorm, many passengers could do nothing but take the train.
【简答题】鱼粉是一种优质蛋白质饲料,但鱼粉中食盐含量也较高,一般为(),含盐量较高的鱼粉应控制用量。
【判断题】2在自动运转过程中,出现非正常情况,人工可随时介入操作。( )
【单选题】. The ship could ______ seventy passengers.
【简答题】All flights ________ because of the snowstorm, many passengers could do nothing but take the train. A) had been canceled B) have been canceled C) were canceled D) having been canceled
【单选题】What could the girl in the ticket office do for the passengers without asking the computer?
A.
She could sell a ticket.
B.
She could write out a ticket.
C.
She could answer the passengers' questions.