分段诊刮时应注意
A．麻醉下进行
B．手术前不宜检查双合诊
C．先用探针探查宫腔深度
D．先刮取宫颈管组织再探宫腔
E．刮取可疑组织应彻底刮宫
参考答案：D
Tony helped his mother _____ the housework last Sunday. [ ]
A. do
B. does
C. did
用字母表示一个数a的n次方为______．
