茶壶盖上为什么有一个小窟窿?()
A、保持茶壶里外的空气压力相同,便于壶内的水倒出
B、保持茶壶里的水新鲜度
参考答案:A
解不等式:
(|3x-1|-1)(sinx-2)>0。
—What are your plans for the weekend?
—_______.[ ]
A. I've no idea
B. I don't know
C. I'd like some holiday
D. I have done the work