带电火灾可选择()灭火器。
A.泡沫
B.干粉
C.水型
D.自制
参考答案:B
Mr. Irvine, who ________ in a high school for forty years, is now living in retirement.
A.had taught
B.taught
C.has taught
D.had been teaching
欧式权证的持有人只有在约定的到期日才有权买卖标的证券,而美式权证的持有人在到期日前的任意时刻都有权买卖标的证券。( )