2.20.1Caesarī omnia ūnō tempore erant agenda: vēxillum prōpōnendum, quod erat īnsigne, cum ad arma concurrī oportēret;Caesar had everything to do at once: the flag had to be raised, which was the signal to run to arms;Note. erant agenda: passive periphrastic, 'had to be done'. The following short clauses all leave out erat or erant: vēxillum prōpōnendum (erat), 'the flag had to be raised'. 2.20.1signum tubā dandum;the signal had to be given with the trumpet; 2.20.1ab opere revocandī mīlitēs;the soldiers had to be called back from the work; 2.20.1quī paulō longius aggeris petendī causā prōcesserant arcessendī;those who had gone a little further to look for material for the rampart had to be fetched;Note. aggeris petendī causā: causā with a genitive gerundive expresses purpose, 'for the sake of fetching material for the rampart'. 2.20.1aciēs īnstruenda;the line had to be drawn up; 2.20.1mīlitēs cohortandī;the soldiers had to be encouraged; 2.20.1signum dandum.the signal had to be given. 2.20.2Quārum rērum magnam partem temporis brevitās et incursus hostium impediēbat.The shortness of the time and the enemy's onrush prevented a great part of these things. 2.20.3Hīs difficultātibus duae rēs erant subsidiō, scientia atque ūsus mīlitum, quod superiōribus proeliīs exercitātī quid fierī oportēret nōn minus commodē ipsī sibi praescrībere quam ab aliīs docērī poterant, et quod ab opere singulīsque legiōnibus singulōs lēgātōs Caesar discēdere nisi mūnītīs castrīs vetuerat.Two things helped against these difficulties: the knowledge and experience of the soldiers, because, trained in earlier battles, they could tell themselves what had to be done no less well than be taught by others; and the fact that Caesar had forbidden his officers to leave the work and their separate legions until the camp was fortified.Note. quid fierī oportēret: indirect question. nisi mūnītīs castrīs: ablative absolute, 'unless the camp had been fortified'.
2.20.4Hī propter propinquitātem et celeritātem hostium nihil iam Caesaris imperium expectābant, sed per sē quae vidēbantur administrābant.Because the enemy were so near and so quick, these officers no longer waited for any order from Caesar, but did on their own what seemed best.