1 if not

2 otherwise

3 else

4 or else

1 whether (or not)

2 if

3 is or isn't

1 is it possible or not?

1 to negate

2 to deny

3 not

1 to negate

2 to deny

3 to reject

4 negative (answer)

5 negation

1 can't recognize Mt Taishan (idiom); fig. not to recognize a famous person

1 extreme sorrow turns to joy (idiom)

1 the country prospers, the people at peace (idiom); peace and prosperity

1 lit. to have eyes but fail to recognize Mt Tai (idiom)

2 fig. to fail to recognize sb important or sb's great talent

3 to be blind to the fact

1 as weighty as Mt Tai, as brilliant as the Big Dipper (idiom); a giant among men