A. when B. that

C. whether D. how

A. is forecasting B. is being forecasting

C. has forecast D. has been forecast

【题目】The explorer could not even strike a match, ________ after the long journey on the freezing day.
A.to freeze
B.freezing
C.frozen
D.to be frozen

【题目】The child enjoyed ________ after outside.
A.to look
B.to be looked
C.being looked
D.looking

A. that B. if

C. what D. that if

【题目】Over the past half century, ________ chemical fertilizers has become very common in farming.
A.having used
B.use
C.used
D.using

【题目】The problems are too complex ________ easily.
A.to be solved
B.to solve
C.solved
D.solving

A. whenever B. whoever C. whichever D. wherever

A. confused; confusing B. confused; confused

C. confusing; confused D. confusing; confusing

A. buy B. bought C. to buy D. to be bought