Many animals sleep a lot when young, but sleep much less when they get older, just________is the case with human being.
He ________ be more than thirty------ he looks so young, just like a teenager!
_________ I traveled by boat, I got seasick.
What a good idea it is that Sarah and Dave are supposed to ______________ as movie characters for the party.
Such a good opportunity may not come again, so you ____________ let it go this time.
The world is changing rapidly and sometimes we find it almost impossible to ________ the advances in science and technology.