Question

If we         now to protect the environment, we’ll live to regret it.

A．hadn't acted

B．haven't acted

C．don't act

D．won't act

Answer 1

C

考查时态。根据if主句的一般将来时态可知从句应使用一般现在时态，且有now作为现在时态的标志词，故选C。