_________ that causes heavy haze sweeping over china remains unknown to many scientists.
A. what it is B. what is it
C. who is it D. who it is
If you put a stone in the way of an ant, it will go around, over, under or on top, without stopping, until it finds a way to get ______ it needs to be.
A. what B. how C. which D. Where
As the Internet is expanding day by day, the opportunities for crime ______ as well.
A. has been B. is C. have been D. are
We will gather for the National High School Basketball game at the school gate at 8 tomorrow morning unless _______.
A．otherwise informing B．otherwise being informed
C．otherwise informed D．having otherwise informed
____ Britain has agreed to join the China-led international development bank - Asian Infrastructure Investment Bank (AIIB), German and Italy will follow suit(跟风，学样).
A. Now that B. In case
C. Even if D. As if
Since the new prohibition of drunk driving_____, the number of accidents in the area has fallen sharply.
A. has been introduced B. introduced
C. was introduced D. has introduced
