【单选题】ARQ中,副台收到W RQ S RQ P A X Y Z则表示7位呼码为_____。
【简答题】(14分,每空2分)某试剂厂用银(含杂质铜)和硝酸(含Fe 3+ )反应制取硝酸银,步骤如下: (1)工业上一般选用中等浓度的硝酸和银反应来制取硝酸银。请在下表空格处填空。 优点 缺点 使用浓硝酸 反应速率快 酸耗较大,产生NO x 的量较多 使用稀硝酸 (2)步骤B加热保温的作用是 : a. 有利于加快反应速率 b.有利于未反应的硝酸挥发 c.有利于硝酸充分反应,降低溶液中H + 的浓度 (3)...
【单选题】To comply with your request, we are quoting you ( ).
【单选题】To comply with your request, we are quoting you
【简答题】When quoting, please state your terms of payment and discount you would allow purchases ______ quantities of not less than 100 dozen ______ individual items. Prices quoted should include insurance and...
【判断题】You should use quotation marks when you are directly quoting hard information.
【简答题】某试剂厂用银(含杂质铜)和硝酸(含Fe 3+ )反应制取硝酸银,步骤如下: (1)工业上一般选用中等浓度的硝酸和银反应来制取硝酸银。请在下表空格处填空。 (2)步骤B加热保温的作用是__________ : a. 有利于加快反应速率 b.有利于未反应的硝酸挥发 c.有利于硝酸充分反应,降低溶液中H+的浓度 (3)步骤C是为了除去Fe 3+ 、Cu 2+ 等杂质,冲稀时产生沉淀的原因是_______...
【多选题】By quoting “If you live each day as if it was your last, someday you’ll most certainly be right”, Jobs meant that _____________________________.
A.
taking each day seriously
B.
there will be one day which is your last day
C.
finally the last day will come if we pray a lot for it
D.
taking every day as your last day may help you find out what is more important in your life.
【简答题】电气化铁路附近发生火灾时,必须立即通知列车调度员、电力调度员或接触网工区值班人员,并遵守哪些规定?
【简答题】(1) 1 1×2 + 1 2×3 + 1 3×4 +…+ 1 9×10 (2)1×2+2×3+3×4+4×5+5×6+6×7.