问题
补全对话，情景问答
把下面的问句和答语搭配起来。
Qs:
( )1. Can I help you?
( )2. What size would you like?
( )3. What would you like on it?
( )4. What's your phone number?
( )5. What's your address?
As:
a. 233 Bridge Street.
b. I'd like mushrooms, onions and cheese.
c. I'd like a pizza, please.
d. I'd like a medium pizza, please.
e. 629-3547.
答案
1. c 2. d 3. b 4. e 5. a
，小车质量为400g，图（b）是打出纸带的一段，相邻计数点间还有四个点未画出，已知打点计时器使用的交流电频率为50Hz，由图可知，打点计时器打纸带上B点时小车的瞬时速度
_______m/s，打纸带上E点时小车的瞬时速度
_________m/s，打点计时器打纸带上B点和打纸带上E点过程中小车克服阻力所做的功为__________J．（g取10m/s2，保留两位有效数字）