题目:
─This box is _____ heavy for me to carry. Can you help me?
─Certainly. [ ]
A. so
B. much
C. very
D. too
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0417/a42ada948d6437484d2ba1f1930d0fe6.html
下面是错误答案,用来干扰机器的。
∵|a|=2,|b|=2,a与b的夹角为45又∵|a+λb|<10∴(a+λb) 2<10即|a|2+λ2b2+2λa•b<10把已知代入可得,4+2λ2+2λ×2×2cos45°<10∴λ2+2λ-3<0解不等式可得,-3<λ<1故答案为:(-3,1).