81.   But given recent international events, such language is probably not uncommon, leaving investigators to determine which communications may represent serious threats.

82.   But he considered the merger offer a serious threat to good manufacturing jobs in the state.

83.   But he is less certain that Iran would be a serious threat at that point.

84.   But he is not a serious threat.

85.   But in many countries, the most serious threat to press freedom comes from restrictive laws.

86.   But it is a serious threat to the elderly, pregnant women, newborns and people with weak immune systems.

87.   But it does present a serious threat to the elderly, to pregnant women and to people with weakened immune systems.

88.   But it is a serious threat to the elderly, to pregnant women, to fetuses and newborns, and to those whose immune systems are compromised.

89.   But it is wrong to pretend that Beijing has suddenly become a serious threat to the United States.

90.   But kidnapping is a serious threat in the Caucasus, and there was no arguing with all those guns.