与999相邻的两个数是998和1000。[ ]
正确
At dawn, they set ____ to get ready for the work of the day.
[ ]
A. up
B. about
C. out
D. in
不属于具有化学危险的散装固体货物的是()
A.焙烧黄铁矿
B.硝酸钡
C.闪锌矿
D.煤