1.幾個不等于零的數(shù)相乘,積的符號由負因數(shù)的________決定,
當負因數(shù)有______個時,積的符號為______
當負因數(shù)有______個時,積的符號為______
2.幾個數(shù)相乘,有一個因數(shù)為零,積就為______
就畫線部分提問
1.My mother works in a hospital
_____________
2.there are fifty students in our class
_____
3.I often have supper at 7 in the evening
____
4.He is reading a book on animals
_________________
5.My mother cooks meals for me every day
_________
6.I'm in Class 2
_______