题目

根据对话内容，从下面方框中选择适当的单词或词组填空，使对话内容完整正确。  Internet,  became homeless,  What was worse,  hear about,  am sorry to A: Did you     90．    the terrible natural disaster in Japan last month? B: Yes. My online friend told me about it on March12th—the day after the disaster. A: I was shocked by the news when I searched the     91．    that afternoon. A lot of people lost their lives and many more    92．     after the earthquake. B:    93．   , a tsunami came after the earthquake. A: Many 选修4-4：坐标系与参数方程 在直角坐标系中，直线的参数方程为：为参数，其中，椭圆的参数方程为为参数)，圆的标准方程为.（1）写出椭圆的普通方程；（2）若直线为圆的切线，且交椭圆于两点，求弦的长.