屏蔽泵又称(),是()的一各特殊结构形式。
A.无填料泵,齿轮泵
B.无填料泵,离心泵
C.无密封泵,齿轮泵
D.无密封泵,离心泵
参考答案:B
阅读短文,判断下列句子正(T)误(F)。
I'm Mike. I'm in Shanghai. It's very hot and sunny now. I can wear my new T-shirt. And my old hat is too
small. I want to buy a new one. But it's too expensive. It's fifty yuan.
( ) 1. It's cool in Shanghai.
( ) 2. Mike has a new T-shirt.
( ) 3. The hat is forty yuan.
( ) 4. It's sunny in Shanghai
项目团队应该了解如何利用统计知识进行质量控制。下面哪一个是项目团队最需要知道的()
A.样本和概率
B.特性样本和变量样本
C.公差和控制限度
D.具体原因和随机原因