问题
选择题
_____ different life today is ____ what it was 20 years ago. [ ]
A. How; from
B. What a; from
C. What; from
D. How; than
答案
答案：A
搜题请搜索小程序“爱下问搜题”
_____ different life today is ____ what it was 20 years ago. [ ]
A. How; from
B. What a; from
C. What; from
D. How; than
答案：A
)(m)，式中k=1 m-1。将一质量为1 kg的光滑小环套在该金属杆上，在P
点给小环以平行于杆、大小为10 m/s的初速，让小环沿杆向+x方向运动，取g=10 m/s2，关于小环的运动，下列说法正确的是
