锡焊接时，允许用酸性、碱性助焊剂。若有氧化不上锡现象时，可用刮刀刮去表面氧化层后再焊。
参考答案：错
— Are you going to visit your grandparents this summer?
— _____ Perhaps my aunt will take me there. [ ]
A. All right.
B. Good idea!
C. I'm not sure.
D. I agree.
汉字机内码中每个字节的最高位均为“1”。
