采用高压有利于提高合成氨（N2 +3H2 →2NH3 ）生产过程的氨产量。
参考答案：对
—What is the matter to you?
—I _____.[ ]
A. get a headache
B. have a headache
C. got a stomachache
D. have good grades
胎盘由以下哪些组织形成
A．滑泽绒毛膜+包蜕膜+羊膜
B．滑泽绒毛膜+底蜕膜+真蜕膜
C．叶状绒毛膜+包蜕膜+真蜕膜
D．叶状绒毛膜十底蜕膜+羊膜
E．叶状绒毛膜+真蜕膜+底蜕膜
