The temperature now is much higher than______of 100 years ago because of more and more greenhouse gas.

The temperature can drop ________zero when winter comes.

A. underB. belowC. at? D. over

The temperature now is much higher than______of 100 years ago because of more and more greenhouse gas.

A．this              B．that              C．it                D．one

The temperature can drop ________zero when winter comes.

A. underB. belowC. at D. over