有关起搏器术语的表述，正确的是（）。

A.感知阈值是指能感知到的最低自身心内电信号的幅度

B.起搏阈值是指能引起心房或心室肌稳定、有效、连续除极的最小起搏电压

C.起搏脉宽代表电脉冲的强度和耗能的时程

D.AV间期是指心房起搏脉冲发放或感知自身P波到心室脉冲发放之间的间期

E.以上都是

I bought a new sweater in a newly-open clothes-market. But what a pity it was that the sweater ______when I washed it.

A．shrank

B．contracted

C．shortened

D．condensed