In one year rats eat 40 to 50 times __________ weight.

Can you imagine<br/>what life will be like in ___ time? A: 50 years’ B: 50 year’s C: 50-years’ D: 50-years

April 18, 1951, France, Italy, Belgium, the Netherlands, Luxembourg and West Germany signed the 50-year Treaty on the establishment of the European Coal and steel community.

The number of students participating in online courses varies 　. A: year to year B: year and year C: year by year D: year on year

This year is the year of Gengzi, and next year is the year of ___________.

At the beginning of the year there was $50 in the cash till and receivables were $2,000. Total sales revenue in the year was $230,000. Receivables at the end of the year were $3,000. Cheques banked from credit sales were $160,000 and cash sales of $50,000 have been banked. There is $100 in the cash till at the year end, but the accountant has discovered that some cash has been stolen.How much cash was stolen during the year? A: $18,950 B: $19,000 C: $19,950 D: $20,950

判定year是否为闰年的表达式是 A: year % 400 == 0 or year % 4 == 0 and year % 100 <> 0 B: year % 400 == 0 or year % 4 == 0 , year % 100 != 0 C: year % 400 == 0 or year % 4 == 0 and year % 100 != 0 D: year % 400 == 0 or year % 4 == 0 , year % 100 <> 0

21（） A: next year B: that year C: this year D: by year

使用变量year代表年份，以下表示判断year是否为闰年的布尔表达式是 。 A: (year % 4 == 0) and (not(year % 100 == 0)) or (year % 400 == 0) B: (year % 4 == 0) and (not(year % 400 == 0)) or (year % 100 == 0) C: (year % 4 == 0) and (year % 100 == 0) or (year % 400 == 0) D: (year % 4 == 0) or (not(year % 100 == 0)) and (year % 400 == 0)

题:(拓展)下面哪些表达式能够判断某年year不是闰年。 A: not(( year%4==0 and year%100 !=0 ) or ( year%400==0 )) B: not( year%4==0 and year%100 !=0 ) and not ( year%400==0 ) C: year%4!=0 or year%100 ==0 and ( year%400 !=0 ) D: year%4==0 and year%100 !=0 or ( year%400==0 )