It was almost five years later _______ he brought back some happy memories.
A.since B.when C.that D.before
It was not in the length of days, but in the use we make of them _______ the value of life lies.
A.when B.where C.that D.how
Maybe all Americans realize that _______ will be the next president will face masses of problems.
A.who B.whoever C.whomever D.no matter who
Doctor Li Wenliang is reported to have been one of the first whistleblowers _______ the epidemic situation.
A.mentioning B.to mention C.mentioned D.mention
We can't imagine what great trouble the medical care personnel had _______ with the COVID-19.
A.fought B.for fighting C.to fight D.fighting
The president is committed to _______ the existing system of medical care.
A.reform B.reforming C.have reformed D.having reformed
