【单选题】能反射无线电波,对于无线电通信有重要意义的是
【单选题】某同学在实验报告中有以下实验数据,其中合理的是( )
D.
用标准NaOH溶液滴定未知浓度的盐酸用去23.120 ml NaOH溶液
【单选题】---How can I get to the post office? ---Walk this road, turn left the third crossing. It’s the right.
【单选题】I was crossing the street and was almost _______ by car.
【单选题】某同学在实验报告中有以下实验数据:①用托盘天平称取11.7g食盐;②用量筒量取5.26mL盐酸;③用广泛pH试纸测得溶液的pH值是3.5,其中数据合理的是( )
【简答题】(15分)(1).某同学在实验报告中写有以下操作和实验数据,其中合理的是 (填编号)_______________。 ① 用托盘天平称取11.7g食盐 ②用量筒量取5.62mL某浓度的盐酸 ③用pH试纸测得某溶液的pH值为3.5 ④滴定某未知浓度的盐酸用去23.15mLNaOH标准溶液 ⑤用500mL容量瓶配制250mL0.1mol/LNa 2 SO 4 溶液 ⑥用酸式滴定管量取25.00mL已知...
【单选题】I was crossing the street and was almost hit by an ( ).
【单选题】Where is the cinema?
A.
It's on the right at the first crossing.
B.
It's on the left at the second crossing.
C.
It's on the right at the second crossing.