垂直式指示曲线的特点是当注水压力不断增大时,而注水量()。
A、逐渐下降
B、保持不变
C、迅速增加
D、上下波动
参考答案:B
看图读句子,判断正误。
( )1. This is Ann's book.
( )2. No food, please.
( )3.The watch is sixteen yuan.
( )4. Don't touch, please.
( )5. This is Wang Ling's ball.
“投递员”译成英文是carrier。