At the time friends visit us in the evening, they often tell us they are in a hurry and look at their watches. It isn’t that our friends are all very busy; it is just that we haven’t got a television. People think that we are very strange. "But what do you do in the evening", they are always asking. The answer is very simple. Both my wife and I have hobbies. We certainly don’t spend our evenings looking at the walls. My wife enjoys cooking and painting and often attends evening classes in foreign languages. This is quite useful as we often go abroad for our holidays. I collect stamps and I’m always busy with my collection. Both of us enjoy listening to the music and playing chess together.
Sometimes there are power cuts and we have no electricity in the house. This does not worry us and we just light candles and carry on with what we were doing before. Our friends, however, are lost—no television! —So they don’t know what to do. On such evenings our house is very full for they all come to us. They all have a good time. Instead of sitting in silence in front of the television, everybody talks and plays games.

The couple have not got a television, because ______.

A．they are not rich enough
B．they are strange people
C．they enjoy spending evenings in their own ways
D．they don’t know what to do when there are power cuts

人工起博器安装的适应症为（）。

A.二度以上房室传导阴滞

B.室上性心动过速

C.病态窦房结综合症

D.室性心动过速

E.房颤