金属凝固后内部化学成分和组织的不均匀现象称为偏析,会影响铸件质量,对()尤为明显。
A.大型铸件
B.中型铸件
C.小型铸件
D.大型锻件
参考答案:A
等比数列{an}中,a1+a3=5,a2+a4=10,则a6+a8等于[ ]
A.80
B.96
C.160
D.320
________ to what you might think, it is safe to swim with AIDS patients in the same pool. [ ]
A. Different
B. Likely
C. Similar
D. Contrary