软体动物表现为身体柔软，不分体节，具有外套、外套膜和贝壳。
参考答案：对
The first edition was published in1955 and _____ a best-seller ever since. [ ]
A. had been
B. will be
C. would be
D. has been
领用原材料过程中不正确的操作是（）
A、核对拟领用原材料的品种、牌号
B、核对拟领用原材料的数量
C、对领出的原材料可以随意码放
D、按照先入先出的原则领出
