受精时，柔荑花序类植物的花粉管从（）处进入胚囊。A.珠孔 B.合点 C.珠被 D.珠

下列化学方程式书写正确的是     

A．C + O₂ ="=" CO₂

B．Zn + HCl ="=" ZnCl₂ + H₂

C．H₂SO₄+NaOH==NaSO₄+H₂O

D．2KMnO₄ K₂MnO₄ + MnO₂ + O₂↑

胸部脊髓横断伤刺激足部皮肤时，出现脊髓自主反射，表现为（）。

A.伸髋、屈膝、背屈踝关节

B.伸髋、伸膝、背屈踝关节

C.屈髋、屈膝、背屈踝关节

D.屈髋、伸膝、跖屈踝关节

E.屈髋、屈膝、跖屈踝关节

以下哪种情形，应当否决其投标（）。

A.投标文件中大写金额与小写金额不一致的

B.投标文件载明的招标项目完成期限超过招标文件规定的期限

C.投标文件中的唱标函与投标函报价不一致

D.投标总价金额与单价金额不一致的

You are proceeding to a distress site and expect large numbers of people in the water. Which statement is TRUE?（）

A.You should stop to windward of the survivors in the water and only use the ship's boats to recover the survivors

B.If the survivors are in inflatable rafts you should approach from windward to create a lee for the survivors

C.An inflatable liferaft secured alongside can be an effective boarding station for transfer of survivors from the boats

D.Survivors in the water should never be permitted alongside due to the possibility of injury from the vessel

加长覆盖电缆线与普通覆盖电缆线外观区别是（）。

A、插头不一样

B、线的颜色不一样

C、线的长度不一样

D、加长覆盖电缆线没有小线抽头