The physician prescribes clomiphene citrate (Clomid) for a woman who has been having difficulty getting pregnant. When preparing the teaching plan for the client about this drug’s potential side effects, which of the following would the nurse include in the teaching plan

A. Increase in fibrocystic breast disease.
B. Increase in congenital anomalies.
C. Multiple pregnancies.
D. Increase in spontaneous abortions.

（6分）在黑箱内有一由四个阻值相同的电阻构成的串并联电路，黑箱面板上有三个接线柱1、2、3。用欧姆表测得1、2接线柱之间的电阻为1Ω，2、3接线柱之间的电阻为1.5Ω，1、3接线柱之间的电阻为2.5Ω。

（1）在虚线框中画出黑箱中的电阻连接方式；

（2）如果将1、3接线柱用导线连接起来，1、2接线柱之间的电阻为______Ω。