【判断题】滚动轴承的规定画法中,各种符号、矩形线框和轮廓线均采用细实线绘制。
【单选题】腹泻患儿脱水纠正后出现明显腹胀,治疗哪项不正确?
【单选题】You want to display the titles of books that meet these criteria: 1. Purchased before January 21, 2001 2. Price is less then $500 or greater than $900 You want to sort the results by their data of pur...
A.
SELECT book_title FROM books WHERE price between 500 and 900 AND purchase_date < '21-JAN-2001' ORDER BY purchase_date;
B.
SELECT book_title FROM books WHERE price IN (500,900) AND purchase_date < '21-JAN-2001' ORDER BY purchase date ASC;
C.
SELECT book_title FROM books WHERE price < 500 or> 900 AND purchase_date < '21-JAN-2001' ORDER BY purchase date DESC;
D.
SELECT book_title FROM books WHERE (price < 500 OR price> 900) AND purchase_date < '21-JAN-2001' ORDER BY purchase date DESC;
【判断题】dh=c p dT 适用于任何工质的定压过程,水蒸气定压汽化过程中 dT=0 ,由此得出结论,水在定压汽化时 dh=c p dT=0 ,此结论是否正确 C. 不确定