每一照明单相分支回路所接光源数不宜超过()个。
A.20
B.25
C.30
D.50
参考答案:B
—I’ll do the washing-up. Jack, would you please do the floors?
—_______.
A.Yes, please
B.No, I don’t
C.Yes, sure
D.No, not at all
儿童学习简单口语的最佳期是()
A.1~2岁
B.2~4岁
C.4~5岁
D.5~6岁