rECEntly, grEAt ADvAnCEs hAvE BEEn mADE in thE stuDy oF vEnus' surFACE By thE usE oF rADAr wAvEs to _________ thE DEnsE ClouD lAyEr.
A．piErCE
B．pEnEtrAtE
C．plungE
D．pErsECutE