在平直公路上有甲、乙两辆汽车同时从同一位置沿着同一方向做匀加速直线运动，它们速度

浅反射不包括下列哪项（）

A.腹壁反射

B.提睾反射

C.角膜反射

D.跖反射

E.桡反射

下列有关二氧化硅的叙述中错误的是（　　）

A．SiO₂是酸性氧化物，它的对应酸是硅酸（H₂SiO₃）

B．二氧化硅易溶于水

C．SiO₂可与CaO或NaOH反应

D．光导纤维的主要原料就是SiO₂

有4个建设方案，各方案的年净现金流量见下表，设折现率为12%，请用净现值法比较， （）方案为相对最优方案。

A．方案A

B．方案B

C．方案D

D．方案C

You are approaching another vessel and see that it has the signal flag “O” hoisted．What is your next action（）.

A.Proceed on present course and speed since the vessel is requesting a pilot

B.Attempt to call the vessel on VHF radiotelephone and begin a search because the vessel has a man overboard

C.Attempt to call the vessel on VHF radiotelephone because it is disabled

D.Approach with caution because the vessel is stopped and making no way through the water

发芽力