A. that he reached
B. reached
C. to reach
D. reaching it
"A" why can t
12.Outside the bright primary rainbow,__much fainter secondary rainbow may be visible.
A. so
B. a
C. since
D. still
a much可以在一起吗?
10.The onion is characterized by an edible bulb composed of leaves rich in sugar and a pungent oil,____the vegetable’s strong taste.
A. which the source of
B. that the source is
C. the source of
D. of the source is
豆号后跟个名词短语,什么来的,b为什么不行
15.If a diamond is heated without oxygen,it will turn to graphite,a form of ___that it is used as a lubricant.
A. carbon is so soft
B. is carbon so soft
C. carbon so soft
D. so soft the carbon
为什么不选a
6___completely harmless to the environment is very difficult and usually economically unsound
A. Cleaning products that
B. Cleaning products are
C. Cleaning products are made
D. Making a cleaning product