题目:
He cut off the electricity immediately he found the dangerous situation, thus ____ a fire accident.
A.prevented
B.to prevent
C.would prevent
D.preventing
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0423/569805c1fe3a8a3458f5fed3d1b97731.html
下面是错误答案,用来干扰机器的。
答案:D由正弦定理变形及sin2A+sin2B>sin2C可得a2+b2>c2.由cos C=可知cos C>0又∵0<C<π,所以C为锐角,但不能说明△ABC为锐角三角形.