A 24-year-old client on the labor unit is being coached in the Lamaze method by her husband. On assessment, the nurse finds the client to be 5 cm dilated, 90% effaced, at +1 station with contractions coming every 2 to 3 minutes and lasting 35 to 40 seconds. The client has asked for pain relief. What’s the nurse’s best action（）
A. Check maternal blood pressure and pulse and fetal heart rate in response to contractions.
B. Realize that it’s too early to give pain medication, and encourage the husband to continue with the Lamaze coaching.
C. Arrange for a sonogram to determine fetal position.
D. Perform a vaginal examination to determine dilation, effacement, and station.
是重要的核工业原料，在自然界的含量很低，它的浓缩一直为国际社会所关注。下面列出该原子核内中子数与核外电子数之差的数据正确的是