未分级天然珍珠(未穿成串) ( )
参考答案：归税号7101.1010，和为11。
解析：按已列目货品归类。
The reason _____ he explained to the teacher was _____ he had forgotten to memorize the new words.[ ]
A. why; because
B. which; because
C. /; that
D. why; that
棉子出苗适于下胚轴伸长温度在（）以上
