题目

 You'd better ____ in an emergency. A. keep still             B. keep calm        C. keep silent       D. keep quiet 答案：B 列竖式计算，带“*”的要验算．*307×118 *25728÷121             3840÷240 552÷69= 608÷32= 982÷32= 510÷85= *208÷24= *289÷17=