装在氨制冷压缩机外部连接管的安全阀，泄漏时连接管会出现（）现象。A.发凉 B.发热

----Whose advice do you think I should take?

----________.

A．It doesn’t matter

B．That’s it

C．It’s up to you

D．Either is OK

什么是回扣？

下列离子方程式正确的是[ ]

A、苛性钾溶液与氢氟酸反应：OH^-+H⁺=H₂O

B、过量NaOH溶液与Ca(HCO₃)₂溶液反应：Ca²⁺+2HCO₃^-+2OH^-=CaCO₃↓+CO₃^2-+2H₂O

C、等物质的量的Ba(OH)₂和NaHSO₄两溶液混合：Ba²⁺+2OH^-+2H⁺+SO₄^2-=BaSO₄↓+2H₂O

D、石英溶于NaOH溶液：Si⁴⁺+2O^2-+2OH^-=SiO₃^2-+H₂O

I went to school ______ my father's car yesterday. [ ]

A. on

B. by

C. in

D. with

蛋白质-能量营养不良皮下脂肪最先消失的部位是

A．面颊部
B．躯干
C．臀部
D．腹部
E．四肢