6． We must_______ a plan to improve your math．A． pick upB． catch up withC． come up withD． make up
6． We must_______ a plan to improve your math．
A． pick up
B． catch up with
C． come up with
D． make up
相关考题：
I believe that a student knows when he has handed ___________ something___________ his usual standard. A. in⋯aboveB. up⋯aboveC. up ... aboutD. in⋯a
Then she cheered_________ a lot when they got the taxi.A. up...overB. of...intoC. of...overD. up...into
Her sister cares much about fashion and her clothes were always.A.up to dateB.up-to dateC.up to-dateD.up-to-date
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. The author mentions"pick-me-up" to indicate that______.A: melatonin levels need to be raisedB: neurohormone can wake us upC: coffee is a stimulantD: decaf is a caffeinated coffee
在选择汽车最小传动比时，为了追求燃油经济性，哪种设计方式最好：（）A．uamax/uP ＞ 1B．uamax/uP = 1C．uamax/uP ＜ 1D．uamax/uP = 0