防止焊补油箱发生爆炸的主要措施是（）
A、放尽燃油
B、用碱水冲洗
C、焊补时敞开油箱口
D、用水反复清洗数次
参考答案：A, B, C, D
—Do you plan to take a vacation this month?
—Yes, we ________ to Hainan and _______ there for five days.
A．go, stay
B．going, staying
C．are going, stay
D．are going, staying
丘疹可见于（）
A.银屑病
B.皮肤淀粉样变
C.扁平疣
D.色素痣
