For this question, it is very important to pay attention to what is implied about the intensity of the weed's effects. It worked slowly to kill the plants. Yes, this does mean that it had "fatal" effect as well as ones that were "destructive" or even "catastrophic" (in a certain sense). The most important point is that it had subtle negative effects that set in over time, ultimately killing all of the plants in the garden. Such subtle, negative activity is best called "pernicious" instead of the other options. Therefore, this is the best option among those provided. 

The sentence implies that the missing adjective should be negative with the word "unfortunately." "Adroit," means clever and "endemic" means common, both of which are good outcomes for a new invention. "Corpulent" means obese which is an irrelevant concept in the sentence. "Obsolete," meaning no longer useful, is better answer than "frightening" because it's common usage is in the context of technology. 

From the context of the sentence it is clear that the two brothers like to cause trouble and do not pay attention to common decency. Another name for common decency is "decorum." "Decorum" is behavior that is in good taste. To provide further help, "animosity" means hatred, ill-feeling; "deity" means God; "temerity" means audacity, excessive confidence, cheek. 

Because the man goes birdwatching every weekend you can reasonably determine that he must be very keen on birdwatching. Someone who is keen can also be described as "avid." To provide further help, "loquacious" means talkative; "serene" means peaceful, calm; "perilous" means dangerous; "timid" means shy. 

From the context of this sentence it is clear that the speaker believes the subject is sneaking around doing something in secretive. So to solve this sentence completion problem you need to determine which of these words means to move stealthily or secretively. The correct answer is therefore "skulk." To provide further help, "leap" means jump high; "amble" means walk slowly and without purpose; "plod" means to walk slowly and heavily; "strut" means to walk with pride and arrogance. 

The context of this sentence is clearly related to cooking. The word "culinary" means related to the art or science of cooking. To provide further help, "assiduous" means hard-working; "cagey" means careful, wary; "oratory" means related to the art or science of speaking; "sterling" means excellent.

The structure of the sentence suggests that the subject of this sentence was already in a gloomy and dejected mood and that that mood was made worse by the bad weather. The correct answer then must mean something like gloomy and grim. This should lead you to "saturnine." To provide further help, "contrite" means remorseful; "drastic" means extreme; "perspicacious" means discerning; "zealous" means overly passionate.

Based on the context of this sentence it is clear that the subject's friends wanted him to be more cheerful so the answer must mean something like not cheerful, miserable and gloomy. The correct answer is therefore "lugubrious." To provide further help, "beneficial" means helpful; "ingenuous" means naive; "incumbent" means highly necessary; "precarious" means dangerous.

From the context of the sentence it is clear that whatever event took place it must have been disastrous and had a terrible effect on the area. The answer choice you are looking for then is an adjective used to describe a devastating natural event. The correct answer is therefore "cataclysmic." To provide further help, "benevolent" means good-natured; "doleful" means sad; "craven" means pathetic and cowardly; "exasperated" means frustrated. 

From context it is clear that the speech must have been pleasant and enjoyable because the whole audience liked it. The correct answer must therefore mean pleasant-sounding so the answer is "euphonious." To provide further help, "parched" means very thirsty; "austere" means severe; "quenched" means satisfied, particularly of a thirst; "tortuous" means long and winding.