According to the periodic table,still some elements undiscovered.

I was ______ tired ______ I fell asleep as soon as I lay down. —Oh, you need to have a good rest.

There are 60 students in my class and 44 of them use weibo veryoften.—44? That means about_______of your classmates are weibo users, right?

I don’t know if it _____tomorrow. If it ____, I will stay at home.

She_______ a new idea for reducing pollution.