A:if , will be invited
B:if, is invited
C:unless, is invited
D:unless , will be invited
读哈尔滨、武汉、北京、广州四地各月平均气温变化曲线和降水量柱状图,回答下列问题.
The two pairs of shoes are tight(紧的)for me. Can I try __________ pair?
已知集合A={x∈R||x|≥2},B={x∈R|x2﹣x﹣2<0}且R为实数集,则下列结论正确的是( )