根据调查者将设计好的问卷交给被调查者,并说明填写要求,当填好后,由调查人员定期收回是()
A、电话调查法
B、邮寄调查法
C、实地调查法
D、留置问卷调查法
参考答案:D
The professor could tell by the ________ look in her eyes that she did not understand a single word
of his lecture. [ ]
A. cold
B. blank
C. innocent
D. fresh
生物的变异现象随处可见,下列变异可以遗传的是[ ]
A.小亮喂养的花猫生了一只白猫
B.小华在纸箱里培育的蒜苗叶片发黄
C.小刚经过严格的训练后跑得很快
D.小林暑假经常到海里游泳皮肤晒得很黑