that，why，whether，what，as if，whatever，because，when，how

（1）The question discussed at the meeting was

that

that

it was worth trying.
（2）We think

that

that

it's necessary to talk with him again.
（3）Do you remember

when/how/why

when/how/why

he came here？
（4）All this was over twenty years ago，but it is

as if

as if

it were only yesterday.
（5）I'm wondering

why

why

you are always late for class.
（6）I am not sure

whether

whether

he is willing to help me.
（7）My parents are very kind to me and always let me do

what

what

I think I should do.
（8）The trouble is

that

that

I lost the key to my room.
（9）I'm a bit sleepy；it's

because

because

I was up all night.
（10）You must do

whatever

whatever

is best for you.