有关腹腔镜气腹早期并发症下列哪一项是正确的（）

A.脑水肿

B.气胸或纵隔气肿

C.气体栓塞

D.心律失常

E.高碳酸血症

We must（）that the experiment is controlled as rigidly as possible.

A.assure

B.secure

C.ensure

D.issue