【B15】______A．thatB．whenC．ifD．because

This is the third week _______ the dustmen haven’t come for the rubbish.A.thatB.whenC

This is the hour______Thailand is always full of political violence.A．thatB．whenC．whereD．h

It is unlikely ____ the world energy will last forever.A: thatB: whichC: becauseD: for

____ in Rome, do as the Romans do.A: AsB: WhenC: BecauseD: After

Animals can move about ____ plants cannot.A: whileB: whenC: becauseD: for

________ he discovered in his experiment is very important to us.A、ThatB、WhenC、WhatD、Whe