221. There are 5 ________ in the passage about nanometer(纳米) technology we have just read. Please tell me the general meaning of the first one.
The doctor said I was over-weight. If only I _____ less!
One of the most important social problems of today is _____ jobs to the unemployed.
The doctor would allow him to go home _____ he remained in bed.
All the girls swam in the lake except two, who _____ halfway.
He regards that book _____ one of the worst that he’s _____ read.