世界上绝大多数植物都能在我国生存，是因为我国（　　）

Betty：Hi, Mum!

Mum：Hello, Betty! Where are you now?

Betty: I'm____ (stand) on the Great Wall of China and____ (talk) to you. Mum：Really? That's great.

Betty：We're on a school trip.

Mum: What about the____(other)? Are they with you?

Betty: Well, right now Tony is ____(eat) a delicious ice cream. Wang Hui is ____take) lots of photos. Daming ____(have) lunch in the sun. And just now Lingling _____(buy) a few presents and postcards. Because they ____(be) on sale in the shop.

Mum: I'd like a postcard too, and please take some photos of the Great Wall and send____(they) to me by email.

Betty: OK. We're enjoying the school trip a lot. Anyway, it's time____(go) back to school now. Bye, Mum!

Mum：Bye, Betty!

二次函数y=ax²+bx+c（a≠0）的图象如图如图所示，若M=a+b﹣c，N=4a﹣2b+c，P=2a﹣b．则M，N，P中，值小于0的数有(   )

2014年3月8日，马来西亚航空公司的MH370次航班发生了失联事件，我国派出多艘舰船进行搜救.其中一艘船的排水量为5000t，海水的密度是1.0×10³kg/m³.（g=10N/kg）请解答下列问题：