The class __________ 80 students is hard to manage.
The space walk will last six and a half hours and the repair of Discovery is expected to __________ a little more than an hour.
I really don’t want a bigger house— I’m __________ with what I’ve got.
It was just a __________ comment; I didn’t mean it to be taken so seriously.
Cycling is highly __________ to people’s health and the environment.
I’ve listened to Professor Smith’s talk about medicine,but I still haven’t got a good understanding of its key _________.