已知抛物线 的准线与双曲线 交于 、 两点,点 为抛物线的焦点,若 为直角三角形,则双曲线离心率的取值范围是____.
漫画《如此美味》中经营者的行为侵犯了消费者的( )
①知情权 ②生命健康权 ③自主选择权 ④公平交易权
{an}是等比数列,且a2=4,a6=16,则a4=( )
⑴play ____
⑵fly ____
⑶watch ____
⑷draw ____
⑸bring ____
⑹can ____
⑺go ____
Replacing some things in your house at the right time can make you healthier. Some researches show us when and why the following things should be replaced.
Word Box: wool羊毛 dry-clean 干洗 bacteria 细菌