质量为的物块沿着直线运动,在外力作用下,其加速度大小逐渐变小。则在这个过程中
A.外力一定做正功
B.位移一定逐渐增加
C.外力的大小一定变小
D.速度的大小一定变小
答案:C
It ____ for three hours and the ground is too wet toplay on, so the sports meet _____. [ ]
A. was raining;has been put off
B. has been raining;has been put off
C. has rained; put off
D. has been raining;has put off
根据《票据法》的规定,有出票人签发、委托办理支票存款业务的银行在见票时无条件支付确定金额给收款人或持票人的票据是( )。
A.银行汇票
B.商业汇票
C.银行本票
D.支票